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506 Electrochemistry, , 13., , [AIEEE 2002], , Electrolytes and Electrolysis, 1., , 2., , 3., , 4., , 5., , 6., , 7., , 8., , 9., , Cathode, Anode, (a) Pure zinc, Pure copper, (b) Impure sample, Pure copper, (c) Impure zinc, Impure sample, (d) Pure copper, Impure sample, In the electrolytic cell, flow of electrons is from, , Which of the following will not conduct electricity in aqueous, solution, [AMU 1982, 83], (a) Copper sulphate, (b) Sugar, (c) Common salt, (d) None of these, 14., Strong electrolytes are those which, [MNR 1983], [IIT Screening 2003], (a) Dissolve readily in water, (a), Cathode, to, anode, in, solution, (b) Conduct electricity, (b) Cathode to anode through external supply, (c) Dissociate into ions at high dilution, (c) Cathode to anode through internal supply, (d) Completely dissociate into ions at all dilutions, (d) Anode to cathode through internal supply, In aqueous solution, strong electrolytes [AMU 1983, 84], 15., An electric current is passed through an aqueous solution of the, (a) Are partially ionized, following. Which one shall decompose [NCERT 1972], (b) Do not ionise, (a) Urea, (b) Glucose, (c) Ionise almost completely, (c) AgNO3, (d) Ethyl alcohol, (d) Form polymers, An electrolyte, [KCET 1984; MP PET/PMT 1988], 16., The electric conduction of a salt solution in water depends on the, (a) Forms complex ions in solution, (a) Shape of its molecules, (b) Gives ions only when electricity is passed, (b) Size of its molecules, (c) Possesses ions even in solid state, (c) Size of solvent molecules, (d) Gives ions only when dissolved in water, (d) Extent of its ionization, Electrolytes when dissolved in water dissociates into ions because[CPMT 1974, 78; MNR 1983], 17., A solution of sodium sulphate in water is electrolysed using inert, (a) They are unstable, electrodes. The products at the cathode and anode are respectively[IIT 1987,96], (b) The water dissolves it, (a) H 2 , O 2, (b) O 2 , H 2, (c) The force of repulsion increases, (c) O 2 , Na, (d) O2 , SO 2, (d) The forces of electrostatic attraction are broken down by water, Electrolyte can conduct electricity because, 18., On electrolysing a solution of dilute H 2 SO 4 between platinum, (a) Their molecules contain unpaired electrons, which are mobile, electrodes, the gas evolved at the anode is, (b) Their molecules contain loosely held electrons which get free, [NCERT 1977, 79; MNR 1980; CBSE PMT 1992], under the influence of voltage, (a), (b) SO 3, SO, (c) The molecules break up into ions when a voltage is applied, 2, (d) The molecules are broken up into ions when the electrolyte is, (c) O 2, (d) H 2, fused or is dissolved in the solvent, 19., The addition of a polar solvent to a solid electrolyte results in, [, Which one of the following metals could not be obtained on, electrolysis of aqueous solution of its salts, [IIT 1990], (a) Polarization, (b) Association, (a) Ag, (b) Mg, (c) Ionization, (d) Non-liberation of heat, (c) Cu, (d) Cr, Which of the following aqueous solution will conduct an electric, current quite well, [MP PMT 1987], (a) Glycerol, (b) HCl, (c) Sugar, (d) Pure water, On the electrolysis of aqueous solution of sodium sulphate, on, cathode we get, [MP PMT 1992, 2002], (a) Na, (b) H 2, (c), , 10., , SO 2, , (d), , 20., , 21., , SO 3, , Electrolysis involves oxidation and reduction respectively at, [CPMT 1973; AMU 1983; NCERT 1983, 84; MH CET 2001], , 11., , 12., , (a) Time consumed, (b) Electro chemical equivalent of electrolysis, (c) Quantity of electricity passed, (d) Mass of electrons, When the sample of copper with zinc impurity is to be purified by, electrolysis, the appropriate electrodes are, , (a) Anode and cathode, (b) Cathode and anode, (c) At both the electrodes, (d) None of the above, Which of the following compounds will not undergo decomposition, on passing electricity through aqueous solution, (a) Sugar, (b) Sodium Chloride, (c) Sodium Bromide, (d) Sodium Acetate, During the electrolysis of an electrolyte, the number of ions produced,, is directly proportional to the, [AFMC 2002], , 22., , During the electrolysis of fused NaCl, which reaction occurs at, anode, [NCERT 1973; AFMC 1992; MP PMT 2002], (a) Chloride ions are oxidized, (b) Chloride ions are reduced, (c) Sodium ions are oxidised, (d) Sodium ions are reduced, The amount of ion discharged during electrolysis is not directly, proportional to, [NCERT 1973], (a) Resistance, (b) Time, (c) Current, (d) Chemical equivalent of the ion, Electrolysis of aqueous HCl solution produces, [CPMT 1987], , (a), , the anode, H[MP, PETat2001], 2 gas, , (b), , H 2 gas at the cathode, , (c), , Cl 2 gas at the cathode

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Electrochemistry, (d), 23., , 24., , 25., , 26., , 28., , (a) Has a low boiling point, (b) Is almost totally unionized, (c) Is neutral, (d) Is readily decomposed, Which is responsible for electrical conduction of molten sodium, chloride, [MADT Bihar 1995], (a) Free electrons, (b) Free ions, (c) Free molecules, (d) Atoms of sodium and chlorine, In electrolysis of aqueous copper sulphate, the gas at anode and, cathode is, [AFMC 1995], (a) O 2 and H 2, (b) SO 2 and H 2, (c), , 29., , 30., , 35., , (d) H  ions produced migrate to the cathode, During electrolysis, the species discharged at cathode are, , 36., , (a) Ions, (b) Cation, (c) Anion, (d) All of these, Electrolysis of molten anhydrous calcium chloride produces, , [AFMC 2000], , [AIIMS 2000], , 37., , Pure water does not conduct electricity because it, [Manipal MEE 1995], , 27., , (a) Hydrogen is liberated at the cathode, (b) Hydrogen is liberated at the anode, (c) There is no reaction, , Cl 2 and O 2 gases both at the anode, , During electrolysis of NaCl solution, part of the reaction is, [NCERT 1984], Na   e   Na. This is termed as, (a) Oxidation, (b) Reduction, (c) Deposition, (d) Cathode reaction, When a solution of an electrolyte is heated the conductance of the, solution, [KCET 1991], (a) Increases because of the electrolyte conducts better, (b) Decreases because of the increased heat, (c) Decreases because of the dissociation of the electrolyte is, suppressed, (d) Increases because the electrolyte is dissociated more, The passage of current liberates H 2 at cathode and Cl 2 at anode., The solution is, [EAMCET 1979,87], (a) Copper chloride in water, (b) NaCl in water, (c) H 2 SO 4, (d) Water, , H 2 and O 2, , (d), , 38., , 39., , CaCl 2 helps in conduction of electricity, , [Kerala (Med.) 2003], , Which of the following metals will give H 2 on reaction with NaOH, , 41., , (a) Mg, (b) Ba, (c) Ca, (d) Sr, Which of the following is not a non electrolyte, (a) Acetic acid, (b) Glucose, (c) Ethanol, (d) Urea, Faraday's, , 1., , Ca   can displace Na from NaCl, , 32., , (d) Ca   can reduce NaCl to Na, Electrolysis is a process in which the cations and anions of the, electrolyte are, [MP PET 1995], (a) Hydrated, (b) Hydrolysed, (c) Charged, (d) Discharged, Degree of ionisation of a solution depends upon, , 33., , (a) Temperature, (b) Nature of the electrolyte, (c) Nature of the solvent, (d) None of these, Which of the following is non-electrolytes, , 31., , [BHU 1998], , 2., , 34., , NaCl, , (b), , CaCl 2, , (c), , C12 H 22 O11, , (d), , CH 3 COOH, , [J & K 2005], , law of electrolysis, , Amount of electricity that can deposit 108 gm of silver from AgNO, solution is, [AFMC 1993; MP PMT 2004], (a) 1 ampere, (b) 1 coulomb, (c) 1 faraday, (d) None of the above, When 9.65 coulombs of electricity is passed through a solution of, silver nitrate (atomic weight of Ag  107.87 taking as 108) the, amount of silver deposited is, , 3, , [EAMCET 1992; KCET 2000], , 3., , (a) 10.8 mg, (b) 5.4 mg, (c) 16.2 mg, (d) 21.2 mg, Three faradays electricity was passed through an aqueous solution of, iron (II) bromide. The weight of iron metal (at. wt. = 56) deposited, at the cathode (in gm) is, [EAMCET 1991], , [KCET (Med.) 1999], , (a), , Diamond, Crystalline sodium chloride, Barium sulphate, Fused potassium chloride, Molten sulphur, , 40., , (b) This mixture has a lower melting point than NaCl, (c), , (b) Cu, , Fe, , (c) Al, (d) Hg, Which one of the following material conducts electricity, (a), (b), (c), (d), (e), , [CBSE PMT 1995], , (a), , (a) Calcium, (b) Phosphorus, (c) Sulphur, (d) Sodium, Which of the following properties of pure metal makes it more, useful then the corresponding alloy, [RPET 2000], (a) It is harder than corresponding alloy, (b) It has high density, (c) It can be extracted easily, (d) It conducts heat and electricity easily, Which of the following liberate hydrogen on reaction with dilute, [Roorkee 2000], H 2 SO 4, (a), , SO 3 and O 2, , Use of electrolysis is, [AFMC 1995], (a) Electroplating, (b) Electrorefining, (c) (a) and (b) both, (d) None of these, Sodium is made by the electrolysis of a molten mixture of about, 40% NaCl and 60% CaCl 2 because, , 507, , 4., , (a) 56, (b) 84, (c) 112, (d) 168, A silver cup is plated with silver by passing 965 coulombs of, electricity, the amount of silver deposited is, [EAMCET 1990; MP PET 1994, 97], , When a molten ionic hydride is electrolysed, [JIPMER 1999], , (a) 9.89 g, , (b) 107.87 g

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508 Electrochemistry, 5., , 6., , 7., , 8., , 9., , 10., , 11., , 12., , 13., , 14., , 15., , (c) 1.0787 g, (d) 1.002 g, 96500, 96500, (c), (d), C, C, The atomic weight of Al is 27. When a current of 5 Faradays is, 3, 2, 18., On passing one faraday of electricity through the electrolytic cells, passed through a solution of Al    ions, the weight of Al, deposited is, [NCERT 1984], containing Ag  , Ni 2 and Cr 3 ions solution, the deposited, (a) 27 gm, (b) 36 gm, Ag ( At. wt .  108), Ni ( At. wt .  59) and Cr ( At. wt .  52) is[AIIMS 1982], (c) 45 gm, (d) 39 gm, Ag, Ni, Cr, An apparatus used for the measurement of quantity of electricity is, known as a, [BHU 1979], (a) 108 gm, 29.5 gm, 17.3 gm, (a) Calorimeter, (b) Cathetometer, (b) 108 gm, 59.0 gm, 52.0 gm, (c) Coulometer, (d) Colorimeter, (c) 108.0 gm, 108.0 gm, 108.0 gm, The unit of electrochemical equivalent is, [EAMCET 1980], (d) 108 gm, 117.5 gm, 166.0 gm, (a) Gram, (b) Gram/ampere, 19., One Faraday of electricity when passed through a solution of copper, sulphate deposits, [CPMT 1978], (c) Gram/coulomb, (d) Coulomb/gram, A certain current liberated 0.504 gm of hydrogen in 2 hours. How, (a) 1 mole of Cu, (b) 1 gm atom of Cu, many grams of copper can be liberated by the same current flowing, (c) 1998], 1 molecule of Cu, (d) 1 gm equivalent of Cu, for the same time in a copper sulphate solution[NCERT 1973, 77; CPMT 1979, 89; AIIMS, 20., When, 1, coulomb, of, charge, is, passed, through electrolyte solution,, (a) 12.7 gm, (b) 15.9 gm, then, the, mass, deposited, is, equal, to, (c) 31.8 gm, (d) 63.5 gm, (a) Equivalent weight, What weight of copper will be deposited by passing 2 Faradays of, (b) 79], Atomic weight, electricity through a cupric salt (Atomic weight of Cu = 63.5)[NCERT 1975; CPMT 1977,, (c), Electrochemical equivalent, (a) 2.0 gm, (b) 3.175 gm, (d) Chemical equivalent, (c) 63.5 gm, (d) 127.0 gm, 21., The platinum electrodes were immersed in a solution of cupric, If the current is passed into the solution of an electrolyte, sulphate and electric current passed through the solution. After, [AIIMS 1979], some time it was found that colour of copper sulphate disappeared, (a) Anions move towards anode, cations towards cathode, with evolution of gas at the electrode. The colourless solution, contains, [NCERT 1984], (b) Anions and cations both move towards anode, (a), Platinum, sulphate, (b), Copper, hydroxide, (c) Anions move towards cathode, cations towards anode, (c) Copper sulphate, (d) Sulphuric acid, (d) No movement of ions takes place, Unit of Faraday is, 22., On passing C ampere of electricity through a electrolyte solution, for t second, m gram metal deposits on cathode. The equivalent, (a) Ampere, (b) Coulomb, weight E of the metal is, [MP PMT 1990], 1, 1, (c) Coulomb mole, (d) Coulomb Sec, C, , t, C, , m, On passing 0.1 Faraday of electricity through aluminium chloride, the, (a) E , (b) E , m  96500, t  96500, amount of aluminium metal deposited on cathode is ( Al  27) [MP PMT 1991], 96500, , m, C,  t  96500, (a) 0.9 gm, (b) 0.3 gm, (c) E , (d) E , C, , t, m, (c) 0.27 gm, (d) 2.7 gm, 23., How, many, Faradays, are, required, to, generate, one, gram atom of, Which of the following represents the first law of Faraday, magnesium from MgCl2, [MADT Bihar 1982], [MP PMT 1991], (a) E  mc 2, (b) E  hv, (c) m  ect, (d) PV  nRT, 24., 5 amperes is passed through a solution of zinc sulphate for 40, minutes. Find the amount of zinc deposited at the cathode[CBSE PMT 1996], (a) 40.65 gm, (b) 4.065 gm, (c) 0.4065 gm, (d) 65.04 gm, 25., In an electroplating experiment m g of silver is deposited, when 4, amperes of current flows for 2 minutes. The amount (in gms ) of, silver deposited by 6 amperes of current flowing for 40 seconds will, be [MNR 1991], (a) 4 m, (b) m / 2, , 16., , (c) m / 4, (d) 2m, On passing 3 ampere of electricity for 50 minutes, 1.8 gram metal, deposits. The equivalent mass of metal is, , 17., , (a) 20.5, (b) 25.8, (c) 19.3, (d) 30.7, The desired amount of charge for obtaining one mole of Al from, Al 3 , (a) 3  96500 C, (b) 96500 C, , 26., , [MP PMT 1992], , 27., , (a) 1, (b) 2, (c) 3, (d) 4, To deposit 0.6354 gm of copper by electrolysis of aqueous cupric, sulphate solution, the amount of electricity required (in coulombs) is, (a) 9650, (b) 4825, (c) 3860, (d) 1930, In electrolysis of a fused salt, the weight of the deposit on an, electrode will not depend on, [CPMT 1973], (a) Temperature of the bath, (b) Current intensity, (c) Electrochemical equivalent of ions, (d) Time for electrolysis, Faraday's laws of electrolysis will fail when, [NCERT 1971], (a) Temperature is increased, (b) Inert electrodes are used, (c) A mixture of electrolytes is used, (d) In none of these cases, According to the first law of Faraday, the weight of a substance, discharge at the electrode is, (a) W  ZQ, (b) W  eF, (c), , W, , Z, It, F, , (d) W  ZI

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Electrochemistry, 28., , 29., , 30., , When 0.04 faraday of electricity is passed through a solution of, CaSO 4 , then the weight of Ca 2  metal deposited at the cathode, is [BHU 1996], (a) 0.2 gm, (b) 0.4 gm, (c) 0.6 gm, (d) 0.8 gm, A current 2.0 A is passed for 5 hours through a molten metal salt, deposits 22 g of metal (At. wt. =177). The oxidation state of the, metal in the metal salt is, [KCET 1996], (a) + 1, (b) + 2, (c) + 3, (d) + 4, How many atoms of calcium will be deposited from a solution of, CaCl 2 by a current of 25 milliamperes flowing for 60 seconds, (a), , 4.68  1018, , (b), , 4.68  1015, , 33., , 34., , 35., , 36., , 37., , 39., , 41., , 42., , (b) 6.28  1018 Coulomb, , (c) 1.6  10 19 Coulomb, (d) None of these, When an electric current is passed through acidulated water 112 ml of, hydrogen gas at N.T.P. collect at the cathode in 965 seconds. The, current passed, in amperes is, , (a) 1.0, (b) 0.5, (c) 0.1, (d) 2.0, How much chlorine will be liberated on passing one ampere current, for 30 minutes through NaCl solution [BVP 2003], (a) 0.66, mole, (b) 0.33 mole, [BHU 1999], (c) 0.66 gm, (d) 0.33 gm, The number of electrons involved in redox reactions when a Faraday, of electricity is passed through an electrolyte in solution is[NCERT 1982; Pb. PMT, (a), , 43., , 6  10 23, , (c) 96500, Coulomb is equal to, (a) ampere  second, (c) watt  second, , (b) 6  10 23, (d) 8  1019, [Orissa JEE 2002], , (a) 35.5 gm, (b) 17.75 gm, (b) ampere  minute, (c) 71 gm, (d) 142 gm, (d) volt  second, What is the amount of chlorine evolved when 2 amperes of current, 44., The, energy, required, to, release, 1, electron, from He  is……., is passed for 30 minutes in an aqueous solution of NaCl [BHU 1998; AIIMS 1999], [Orissa JEE 2002], (a) 66 g, (b) 1.32 g, (a) + 54.4 eV, (b) – 13.6 eV, (c) 33 g, (d) 99 g, (c) + 27.2 eV, (d) Cannot be predicted, On passing a current through KCl solution, 19.5 g of potassium, 45., Faraday's laws of electrolysis are related to the, [IIT 1983], is deposited. If the same quantity of electricity is passed through a, (a) Atomic number of cation, solution of aluminium chloride, the amount of aluminium deposited, (b) Atomic number of anion, is [EAMCET 1997], (c) Equivalent weight of the electrolyte, (a) 4.5 g, (b) 9.0 g, (d) Speed of the cation, (c) 13.5 g, (d) 27 g, 46., The electric charge for electrode decomposition of one gram, (e) None is correct, equivalent of a substance is, [IIT 1984; KCET 1992], Electrolysis rules of Faraday’s states that mass deposited on, (a), One, ampere, per, second, electrode is proportional to, [CBSE PMT 2000], (b) 96500 coulombs per second, (a) m  I 2, (b) m  Q, (c) One ampere for one hour, 2, (d) Charge on one mole of electrons, (c) m  Q, (d) None of these, 47., The number of electrons passing per second through a cross-section, A current being passed for two hour through a solution of an acid, of copper wire carrying 10 6 amperes of current per second is, liberating 11.2 litre of oxygen at NTP at anode. What will be the, found to be, [EAMCET 1985], amount of copper deposited at the cathode by the same current, 19, 35, when passed through a solution of copper sulphate for the same, (a) 1.6  10, (b) 6  10, time [BVP 2003], 16, (c), (d) 6  1012, 6, , 10, (a) 16 g, (b) 63 g, 48., The electrolytic cells, one containing acidified ferrous chloride and, (c) 31.5 g, (d) 8 g, another acidified ferric chloride are connected in series. The ratio of, In a metal oxide, there is 20% oxygen by weight. Its equivalent, iron deposited at cathodes in the two cells when electricity is passed, weight is, [Pb. PMT 2000], through the cells will be, (a) 40, (b) 64, [CPMT 1989], (c) 72, (d) 32, (a) 3 : 1, (b) 2 : 1, On the basis of the information available from the reaction, (c) 1 : 1, (d) 3 : 2, 4, 2, 49., When 96500 coulomb of electricity is passed through a copper, Al  O2  Al2O3 , G  827kJmol 1, of, the, O2, 3, 3, sulphate solution, the amount of copper deposited will be[MP PMT 1996], minimum emf required to carry out an electrolysis of Al2 O3 is (F, (a) 0.25 mol, (b) 0.50 mol, (c) 1.00 mol, (d) 2.00 mol, = 96500C mol 1 ), [CBSE PMT 2003], (a) 8.56 V, (b) 2.14 V, 50., During electrolysis of fused aluminium chloride 0.9 gm of, (c) 4.28 V, (d) 6.42 V, aluminium was deposited on the cathode. The volume of chlorine, Then during electrolysis of a solution of AgNO , 9650 coulombs of, liberated at the anode will be, charge pass through the electroplating bath, the mass of silver, (a) 2.24 litres, (b) 11.2 litres, deposited in the cathode will be, (c) 1.12 litres, (d) 5.6 litres, [AIEEE 2003], 51., Faraday has the dimensions of, [MP PET 1995], (a) 1.08 g, (b) 10.8 g, (a) Coulombs, (c) 21.6 g, (d) 108 g, (b) Coulomb equivalent, Total charge on 1 mole of a monovalent metal ion is equal to, (c) Coulomb per equivalent, [DPMT 2001], (d) Coulomb per degree Kelvin, ,, , 38., , 9.65  10 4 Coulomb, , [MNR 1991; UPSEAT 2001], , 9, , [BHU 1997; RPET 1999], , 32., , 40., , (c) 4.68  10, (d) 4.68  10, On passing 0.5 faraday of electricity through NaCl , the amount of, Cl deposited on cathode is, 12, , 31., , (a), , 509, , 3

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510 Electrochemistry, 52., , 53., , 54., , [AMU 1983; AFMC 1989; MP PET 2001], , The required charge for one equivalent weight of silver deposite on, cathode is, [Roorkee 1995], (a), , 9.65  10 7 C, , (b), , 9.65  10 4 C, , (a), , 63.5 gm Cu, , (b), , 31.75 gm Cu, , (c), , 96500 gm Cu, , (d) 100 gm Cu, , (a), , 56., , A current of strength 2.5 amp was passed through CuSO 4, solution for 6 minutes 26 seconds. The amount of copper deposited, is, (Atomic weight of Cu  63.5 ), (1 faraday = 96500 coulombs), , 64., , 65., , (a) 0.3175 g, (b) 3.175 g, (c) 0.635 g, (d) 6.35 g, A certain quantity of electricity is passed through an aqueous, solution of AgNO 3 and cupric salt solution connected in series., The amount of Ag deposited is 1.08 gm , the amount of copper, deposited is (atomic weight of Cu = 63.5; Ag = 108), (a) 0.6454 g, (b) 6.354 g, (c) 0.3177 g, (d) 3.177 g, The number of electrons required to deposit 1gm atom of, aluminium (at. wt. = 27) from a solution of aluminium chloride will, be (where N is Avogadro's number), (a) 1 N, (b) 2 N, (c) 3 N, (d) 4 N, Three faradays of electricity are passed through molten Al 2 O 3 ,, , 66., , 67., , 58., , 59., , 60., , 61., , platinum electrodes. A current is passed until 1.6 gm of O 2 has been, liberated at anode. The amount of silver deposited at cathode would, be, [CPMT 1971], (a) 107.88 gm, (b) 1.6 gm, (c) 0.8 gm, (d) 21.60 gm, The aqueous solution of which of the following decomposes on, passing electric current, [EAMCET 1973], (a) Canesugar, (b) Urea, (c) Methanol, (d) Potassium iodide, The number of Faradays needed to reduce 4 gram equivalents of, Cu   to Cu metal will be, [BHU 1981], (a) 1, (b) 2, (c) 1/2, (d) 4, When electricity is passed through the solution of, AlCl3 , 13.5 gm of Al are deposited. The number of Faraday, must be, , 62., , (b) 1.00, (d) 2.00, , When one of ampere current flows for 1 sec through a conductor,, this quantity of electricity is known as, (a) Faraday, (b) Coulomb, (c) E.M.F., (d) Ohm, The mass deposited at an electrode is directly proportional to, (a) Atomic, weight, (b) Equivalent weight, [EAMCET, 1986], (c) Molecular weight, (d) Atomic number, From the solution of which of the following one faraday of electricity, will liberate one gram atom of metal, (a), , NaCl, , (b), , BaCl2, , (c), , CuSO 4, , (d), , AlCl3, , 68., , On electrolysis, 1 mole of aluminium will be deposited from its, molten salt by, [MH CET 2000], (a) 3 moles of electrons, (b) 4 moles of electrons, (c) 2 moles of electrons, (d) 1 mole of electrons, , 69., , The atomic weight of Fe is 56. The weight of Fe deposited from, FeCl3 solution by passing 0.6 Faraday of electricity is, [MH CET 2000], , (a) 5.6 g, (c) 22.4 g, 70., , (b) 11.2 g, (d) 33.6 g, , 2.5 F of electricity are passed through a CuSO 4 solution. The, number of gm equivalent of Cu deposited on anode is, [CPMT 1973; DPMT 1982; MP PMT 2001], , 71., , 72., , 73., , [NCERT 1974; MP PET 1992; MP PMT 1994], , (a) 0.50, (c) 1.50, The value of one Faraday is, , [MP PET/PMT 1998], , 48,250, 10,000, , [MHCET 1999; MP PET 1993,2000; AFMC 2000], , [BHU 1990], , (a) 1 mole : 2 mole : 3 mole, (b) 3 mole : 2 mole : 1mole, (c) 1 mole : 1.5 mole : 3 mole, (d) 1.5 mole : 2 mole : 3 mole, An electrolytic cell contains a solution of Ag 2 SO 4 and have, , 48250 Coulombs, 193000 Coulombs, the deposition of 107.870 g of, , [CPMT 1974; AFMC 1987; MP PET 2000], , aqueous solution of CuSO 4 and molten NaCl taken in different, electrolytic cells. The amount of Al, Cu and Na deposited at the, cathodes will be in the ratio of, , (a) 48250 Faradays, (b), (c) 193000 Faradays, (d), The number of coulombs required for, silver is, (a) 96,500, (b), (c) 1,93,000, (d), , [MP PMT 1993], , [AIIMS 1992], , 57., , (b) 96550 C mol 1, , (c) 96500 C mol 1, (d) 98500 C mol 1, (c) 9.65  10 3 C, (d) 9.65  10 5 C, 63., The quantity of electricity needed to liberate 0.5 gram equivalent of, 96500 coulombs of electric current liberates from CuSO 4 solution[MP PMT 1995]an element is, [CPMT 1988; MP PMT 1997], , [EAMCET 1989; MP PET 1994], , 55., , 95500 C mol, , 1, , 74., , (a) Zero, (b) 1.25, (c) 2.5, (d) 5.0, The equivalent weight of a certain trivalent element is 20. Molecular, weight of its oxide is, [KCET 2003], (a) 152, (b) 56, (c) 168, (d) 68, Silver is removed electrically from 200 ml of a 0.1 N solution of, AgNO3 by a current of 0.1 ampere. How long will it take to, remove half of the silver from the solution, [AMU 1999], (a) 16 sec, (b) 96.5 sec, (c) 100 sec, (d) 10 sec, In order to separate oxygen from one mole of H 2 O the required, quantity of coulomb would be, [RPET 1999], (a) 1.93  10 5, (b) 9.6  10 4, (c) 1.8, (d) 3.2, A current of 0.25A is passed through CuSO 4 solution placed in, voltameter for 45 minutes. The amount of Cu deposited on cathode, is (At weight of Cu  63.6 ), [BHU 2001]

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Electrochemistry, , 75., , 76., , 77., , 78., , (a) 0.20 g, (b) 0.22 g, (c) 0.25 g, (d) 0.30 g, Faraday constant, [KCET (Med.) 2001], (a) Is a numerical constant, (b) Depends on equivalent, (c) Depends upon the current passed, (d) Depends on the number of electrons, If 0.5 amp current is passed through acidified silver nitrate solution, for 10 minutes. The mass of silver deposited on cathode, is (eq. wt., of silver nitrate = 108), [AFMC 2001], (a) 0.235 g, (b) 0.336 g, (c) 0.536 g, (d) 0.636 g, The unit for the electric current is, [KCET (Med.) 2001], (a) Ohm, (b) Volt, (c) Ampere, (d) Coulomb, The quantity of electricity required to liberate, hydrogen at STP from acidified water is, , 88., , 90., , [KCET (Med.) 2001], , 79., , 80., , 81., , 82., , 83., , (a), , 11.2 dm 3, , (b), , (c), , 22.4 dm 3, , (d) 1.0 dm 3, , 84., , 85., , 86., , 87., , 91., , 92., , 93., , 4.68  1015, , (c) 4.68  1012, (d) 4.68  10 9, The number of coulombs required to reduce 12.3 g of nitrobenzene, to aniline, [UPSEAT 2003], (a) 115800 C, (b) 5790 C, (c) 28950 C, (d) 57900 C, During the process of electrolytic refining of copper, some metals, present as impurity settle as 'anode mud'. These are, (a) Sn and Ag, (b) Pb and Zn, (c) Ag and Au, (d) Fe and Ni, A galvanic cell is set up from a zinc bar weighing 50g and 1.0litre, 1.0M,, CuSO 4 solution. How long would the cell run, assuming it delivers a, steady current of 1.0 ampere, (a) 48 hrs, (b) 41 hrs, (c) 21 hrs, (d) 1 hr, On passing electric current through molten aluminium chloride, 11.2, litre of Cl 2 is liberated at NTP at anode. The quantity of, aluminium deposited at cathode is (at. wt. of Al = 27), (a) 9 g, (b) 18 g, (c) 27 g, (d) 36 g, An electric current is passed through silver voltameter connected to, a water voltameter. The cathode of the silver voltameter weighed, 0.108 g more at the end of the electrolysis. The volume of oxygen, evolved at STP is, [Kerala (Med.) 2003], , (a) 56 cm, , 3, , (b) 550 cm, , 3, , (d) 11.2 cm, , (c) 5.6 cm, , (e) 22.4 cm, , Charge required to liberate 11.5 g sodium is, (a) 0.5 F, (b) 0.1 F, (c) 1.5 F, (d) 96500 coulombs, In the electrolysis of water, one Faraday of electrical energy would, evolve, [DCE 2004], (a) One mole of oxygen, (b) One g atom of oxygen, (c) 8 g of oxygen, (d) 22.4 litres of oxygen, In a galvanic cell, the electrons flow from, [KCET 2004], (a) Anode to cathode through the solution, (b) Cathode to anode through the solution, (c) Anode to cathode through the external circuit, (d) Cathode to anode through the external circuit, An electric current is passed through silver nitrate solution using, silver electrodes. 10.79 g of silver was found to be deposited on the, cathode if the same amount of electricity is passed through copper, sulphate solution using copper electrodes, the weight of copper, deposited on the cathode is, [Kerala PMT 2004], (a) 6.4 g, (b) 2.3 g, (c) 12.8 g, (d) 1.6 g, (e) 3.2 g, The law of electrolysis were proposed by, , (b), , [Roorkee 2000], , 5.6 dm 3, , [AIIMS 1992; DCE 2002], , 4.68  1018, , [AIEEE 2005], , 112 cm 3 of, , (a) 0.1 Faraday, (b) 1 Faraday, (c) 965 Coulomb, (d) 96500 Coulomb, Which solution will show highest resistance during the passage of, current, [BHU 2001], (a) 0.05 N NaCl, (b) 2 N NaCl, (c) 0.1 N NaCl, (d) 1 N NaCl, 4 g of copper was dissolved in concentrated nitric acid. The copper, nitrate solution on strong heating gave 5 g of its oxide. The, equivalent weight of copper is, [KCET 2004], (a) 23, (b) 32, (c) 12, (d) 20, The amount of silver deposited by passing 241.25 coulomb of, current through silver nitrate solution is, [MHCET 2003], (a) 2.7 g, (b) 2.7 mg, (c) 0.27 g, (d) 0.54 g, When 1F of electricity is passed through acidulated water,, [MHCET 2004], O 2 evolved is, , [CPMT 1982;Pb.CET 2003], (a) Kohlraush, (b) Faraday, (c) Nernst, (d) Berthelot, How many atoms of calcium will be deposited from a solution of, CaCl 2 by a current 0.25 mA following for 60 seconds, (a), , 89., , 511, , 94., , 3, , 3, , 3, , During electrolysis of aqueous NaOH, 4 g of O 2 gas is liberated, at NTP at anode, H 2 gas liberated at cathode is, [CBSE PMT 1998], , (a) 2.8 litres, (c) 11.2 litres, , (b) 5.6 litres, (d) 22.4 litres, , Conductor and conductance, 1., , Which one of the following statements is correct, [MP PET 1997], , (a) The oxidation number of oxygen in KO 2 is zero, (b) The specific conductance of an electrolyte solution decreases, with increase in dilution, , 2., , (c), , Sn 2  oxidises Fe 3 , , (d), , Zn / ZnSO 4 is a reference electrode, , In infinite dilutions, the equivalent conductances of Ba 2  and Cl , are 127 and 76 ohm 1cm 1 eqvt 1 . The equivalent conductivity, of BaCl2 at indefinite dilution is [CBSE 2000], (a) 101.5, , (b) 139.5

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512 Electrochemistry, 3., , 4., , (c) 203.5, (d) 279.5, The factor which is not affecting the conductivity of any solution is, (a) Dilution, (b) Nature of electrolyte, (c) Temperature, (d) None of these, Specific, conductance, of, 0.1, m, nitric, acid, is, 6.3  10 2 ohm 1cm 1 . The molar conductance of solution is, [Kerala (Med.) 2003], 1, , 2, , (a) 630 ohm cm mole, 1, , 2, , (c) 100 ohm cm mole, 5., , 6., , 7., , 8., , 9., , 10., , 11., , 12., , 13., , 1, , 1, , 1, , (b) 315 ohm cm 2mole 1, (d) 6300 ohm 1cm 2mole 1, , (c) ohm cm 2 (gm equivalent), , S cm 2, It has been observed that gaseous hydrogen chloride is a very poor, conductor of electricity but a solution of hydrogen chloride gas in, water is a good conductor of electricity. This is due to the fact that[NCERT 1976, (a) Water is good conductor of electricity, (b) Hydrogen chloride gas in water solution ionizes, (c) A gas is non-conductor but a liquid conducts electricity, (d) Gas does not obey Ohm's law whereas solution does, Electrolytic conduction differs from metallic conduction in that in, the case of electrolytic conduction, (d), , 14., , 15., (e) 63.0 ohm 1cm 2mole 1, [KCET 1987; Bihar CEE 1992], The conductivity of strong electrolyte is, [CPMT 2003], (a) The resistance increases with increasing temperature, (a) Increase on dilution slightly, (b) The resistance decreases with increasing temperature, (b) Decrease on dilution, (c) The flow of current does not generate heat, (c) Does not change with dilution, (d) The resistance is independent of the length of the conductor, (d) Depend upon density of electrolytes itself, 16., The electrolytic conductance is a direct measure of, If X is the specific resistance of the solution and M is the molarity of, [KCET 1990; CPMT 2003], the solution, the molar conductivity of the solution is given by[Kurukshetra CEE 2002], (a) Resistance, (b) Potential, 1000 X, 1000, (c) Concentration, (d) Dissociation, (a), (b), 17., Conductivity of a strong electrolyte, [KCET 1993], M, MX, (a), Increases, on, dilution, 1000 M, MX, (c), (d), (b) Does not change considerably on dilution, X, 1000, (c) Decreases on dilution, Conductivity (unit Siemen’s) is directly proportional to area of the, (d) Depends on density, vessel and the concentration of the solution in it and is inversely, 18., Which of the following statements is not applicable to electrolytic, proportional to the length of the vessel then the unit of the constant, conductors, [AIIMS 1991], of proportionality is, [AIEEE 2002], (a), New, products, show, up, at, the, electrodes, (a) Sm mol 1, (b) Sm 2 mol 1, (b) Ions are responsible for carrying the current, (c) Show a positive temperature coefficient for conductance, (c) S 2 m 2 mol, (d) S 2m 2 mol 2, (d) A single stream of electrons flows from cathode to anode, If one end of a piece of a metal is heated, the other end becomes hot, 19., Which one is not a conductor of electricity, [RPET 1999], after some time. This is due to, (a) NaCl (aqueous), (b) NaCl (solid), [CBSE PMT 1995], (a) Energised electrons moving to the other part of the metal, (c) NaCl (molten), (d) Ag metal, (b) Resistance of the metal, 20., Solid sodium chloride is bad conductor of electricity because, (c) Mobility of atoms in the metal, (a) It contains only molecules, (d) Minor perturbation in the energy of atoms, (b) It does not possess ions, Conductivity of a solution is directly proportional to, (c) The ions present in it are not free to move, [KCET 1984], (d) It does not contain free molecules, (a) Dilution, (b) Number of ions, 21., Which of the following is a poor conductor of electricity, [EAMCET 1992], (c) Current density, (d) Volume of the solution, The increase in equivalent conductance of an electrolyte solution, (a) CH 3 COONa, (b) C 2 H 5 OH, with dilution is due to the increase in, (c) NaCl, (d) KOH, [MP PMT 1996], 22., The molar conductivity is maximum for the solution of, (a) Ionic attraction, concentration, [DCE 2002], (b) Molecular attraction, (a) 0.001 M, (b) 0.005 M, (c) Degree of association of the electrolyte, (c) 0.002 M, (d) 0.004 M, (d) Degree of ionisation of the electrolyte, 23., The unit of molar conductivity is, [DCE 2002], Which of the following conducts electricity, [AFMC 1995], 1, 2, 1, 2, 1, (a)  cm mol, (b)  cm mol, (a) Fused NaCl, (b) CO 2, (c) 1cm 2mol 1, (d)  cm 2mol, (c) Br2, (d) Si, 24., The highest electrical conductivity of the following aqueous solutions, Which of the following shows electrical conduction, is of, [AIEEE 2005], [CBSE PMT 1999; AIIMS 1999], (a) 0.1 M acetic acid, (b) 0.1 M chloroacetic acid, (a) Potassium, (b) Graphite, (c) 0.1 M fluoroacetic acid, (d) 0.1 M difluoroacetic acid, (c) Diamond, (d) Sodium, 1, 25., Given l / a  0.5 cm , R  50ohm, N  1.0 . The equivalent, The unit of equivalent conductivity is, conductance of the electrolytic cell is [Orissa JEE 2005], [CPMT 1999; BCECE 2005], (a) ohm cm, (b), , 1, , 2, , ohm cm (gm equivalent), , 1, , (a), , 10 ohm 1 cm 2 gm eq 1, , (b), , 20 ohm 1 cm 2 gm eq 1, , (c), , 300 ohm 1 cm 2 gmeq 1, , (d) 100ohm 1 cm 2 gmeq 1

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Electrochemistry, 26., , If equivalent conductance of 1 M benzoic acid is 12.8 ohm 1 cm 2, and if the conductance of benzoate ion and H  ion are 42 and, 288.42 ohm 1 cm 2 respectively. its degree of dissociation is, (a) 39%, (c) 0.35%, , 27., , (d), 8., , (b) 3.9%, (d) 0.039%, , The unit ohm 1 is used for, (a) Molar conductivity, (c) Specific conductivity, , [J & K 2005], , (b) Equivalent conductivity, (d) Conductivity, , 9., , 2., , When electric current is passed through a cell having an electrolyte,, the positive ions move towards the cathode and the negative ions, towards the anode. If the cathode is pulled out of the solution [AIIMS 1980]10., (a) The positive and negative ions will move towards the anode, (b) The positive ions will start moving towards the anode, the, negative ions will stop moving, (c) The negative ions will continue to move towards the anode and, the positive ions will stop moving, (d) The positive and negative ions will start moving randomly, If the half cell reaction A  e   A  has a large negative, reduction potential, it follows that, , 11., , [MNR 1992; UPSEAT 2000, 02], , (a), 3., , 4., , A is readily reduced, , (b), , A is readily oxidised, , (c) A  is readily reduced, (d) A  is readily oxidised, Mark the false statement, [MP PET 1997], (a) A salt bridge is used to eliminate liquid junction potential, (b) The Gibbs free energy change, G is related with, electromotive force (E) , as G  nFE, (c) Nernst equation for single electrode potential is, RT, E  Eo , ln a M n , nF, (d) The efficiency of a hydrogen oxygen fuel cell is 23%, , 12., , 13., , 5., , 6., , 7., , (b), , (c) 0.918 cm 1, (d) 1.12 cm 1, Which of the following reactions occurs at the cathode of a common, dry cell, [NCERT 1978], (a), , Mn  Mn 2   2e , , (b), , 2 MnO2  Zn 2   2e   ZnMn2 O4, 2, , (c), , 2 ZnO2  Mn, , (d), , Zn  Zn 2   2e , , , ,  2e  MnZn2 O4, , In Cu  Zn cell, [BHU 1981], (a) Reduction occurs at the copper cathode, (b) Oxidation occurs at the copper cathode, (c) Reduction occurs at the anode, (d) Chemical energy is converted to light energy, Which of the following reaction is used to make a fuel cell, Cd (s)  2 Ni(OH)3 (s)  CdO(s)  2 Ni(OH )  H 2 O(l), , (b), , Pb(s)  PbO2 (s)  2 H 2 SO 4 (aq)  2 PbSO4 (s)  2 H 2 O(l), , (c), , 2 H 2 (g)  O2 (g)  2 H 2 O(l), , H 2 SO 4 is regenerated, , (c), , PbSO4 is deposited on lead electrode, , (d) Lead is deposited on lead electrode, When lead storage battery is charged, (a) Lead dioxide dissolves, (b) Sulphuric acid is regenerated, (c) The lead electrode becomes coated with lead sulphate, (d) The amount of sulphuric acid decreases, The electrolytic decomposition of dilute sulphonic acid with, platinum electrode in cathodic reaction is, [MNR 1988; UPSEAT 1999, 2002], , (a) Oxidation, (b) Reduction, (c) Oxidation and reduction both, (d) Neutralisation, Which colourless gas evolves, when NH 4 Cl reacts with zinc in a, dry cell battery, [Orissa JEE 2003], (a) NH 4, (b) N 2, (d) Cl 2, , H2, , Which of the substances Na, Hg, S , Pt and graphite can be used, as electrodes in electrolytic cells having aqueous solutions, (a) Na, Pt and graphite, (b) Na and Hg, (c) Pt and graphite only, (d) Na and S only, In electrolysis of dilute H 2 SO 4 using platinum electrodes, (a), , H 2 is evolved at cathode, , (b), , NH 3 is produced at anode, , (c), , Cl 2 is obtained at cathode, , For cell reaction, Zn  Cu 2   Zn 2   Cu, cell representation is, (a) Zn | Zn | Cu |Cu, (b) Cu | Cu | Zn | Zn, (c) Cu | Zn | Zn | Cu, (d) Cu | Zn | Zn | Cu, Which one is not called a anode reaction from the following, 2+, , 2+, , 15., , 2+, , 2+, , 2+, , 1, Cl 2  e , 2, , (a), , Cl  , , (c), , Hg   Hg    e , , 2+, , 2+, , 2+, , (b) Cu  Cu    2e , (d), , Zn 2   2e   Zn, , 16., , A cell from the following which converts electrical energy into, chemical energy, (a) Dry cell, (b) Electrochemical cell, (c) Electrolytic cell, (d) None of these, , 17., , In the cell Zn | Zn 2  || Cu 2  | Cu, the negative electrode is, [MP PMT 1995], , (a), , [AIIMS 2003], , (a), , (b), , (d) O 2 is produced, 14., , 0.66 cm 1, , [MP PET 2003], , [DPMT 1983; IIT 1983; Kurukshetra CET 2002; AFMC 2005], , [CBSE PMT 1999, 2000; KCET 2001], , 0.142 cm 1, , When lead storage battery is charged, [DPMT, (a) PbO, dissolved, 2 is 2005], , (c), , The specific conductance of a 0.1 N KCl solution at 23 o C is, 0.012 ohm 1 cm 1 . The resistance of cell containing the solution, at the same temperature was found to be 55 ohm. The cell constant, will be, (a), , 2 Fe(s)  O 2 (g)  4 H  (aq)  2 Fe 2  (aq)  2 H 2 O(l), , [MP PET 1993; MP PMT 2000], , Cell constant and Electrochemical Cells, 1., , 513, , 18., , Cu, , (b) Cu, , 2, , (c) Zn, (d) Zn 2 , Which of the following statements is correct ? Galvanic cell converts[KCET 1991;, (a) Chemical energy into electrical energy, (b) Electrical energy into chemical energy, (c) Metal from its elemental state to the combined state

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514 Electrochemistry, 19., , 20., , 21., , 22., , 23., , (d) Electrolyte into individual ions, 29., Which one of the following statement is true for a electrochemical, cell1999], [Pb. PMT 1999; KCET 1999], Hydrogen–oxygen fuel cells are used in space–craft to supply [MP PMT 1993; MP PET, (a) H 2 is cathode and Cu is anode, (a) Power for heat and light, (b) Power for pressure, (b) H 2 is anode and Cu is cathode, (c) Oxygen, (c) Reduction occurs at H 2 electrode, (d) Water, (d) Oxidation occurs at Cu electrode, The standard cell potential of Zn | Zn 2 (aq ) || Cu 2 (aq ) | Cu cell is, 30., In the reaction, 1.10 V. The maximum work obtained by this cell will be, [MP Cu, PET(s2002], )  2 Ag  (aq)  Cu 2 (aq)  2 Ag(s), (a) 106.15 kJ, (b) – 212.30 kJ, The reduction half-cell reaction is, [AIIMS 1997], (c) – 318.45 kJ, (d) – 424.60 kJ, (a) Cu  2e   Cu 2, (b) Cu  2e   Cu 2, The relationship between standard reduction potential of cell and, equilibrium constant is shown by, [MP PET 2002], (c) Ag   e   Ag, (d) Ag  e   Ag , 31., Which of the following statements about galvanic cell is incorrect[JIPMER 1997], 0 .059, n, 0, 0, (a) Ecell, (b) Ecell, , log K c, , log K c, (a) Anode is positive, 0 .059, n, (b) Oxidation occurs at the electrode with lower reduction, log K c, potential, 0, 0, (c) Ecell  0.059 n log Kc, (d) Ecell , (c) Cathode is positive, n, (d) Reduction occurs at cathode, Consider the Galvanic cell Zn  | ZnSO 4 || CuSO 4 | Cu  the, 32., The molar conductances of NaCl, HCl and CH 3 COONa at, reaction at cathode is, [AMU 2000], infinite dilution are 126.45, 426.16 and 91 ohm 1 cm 2 mol 1, , (a) Zn 2  2e   Zn, respectively. The molar conductance of CH 3 COOH at infinite, (b) Cu 2   2e   Cu, dilution is, [CBSE PMT 1997], (c), , Cu 2   Zn  Cu  Zn 2 , , (a), , 201.28 ohm 1 cm 2 mol 1, , (d), , Zn 2   Cu  Zn  Cu 2 , , (b), , 390.71 ohm 1 cm 2 mol 1, , (c), , 698.28 ohm 1 cm 2 mol 1, , The cell reaction Cu  2 Ag   Cu 2  Ag is best represented, by, [AMU 2000], (a), , Cu(s) | Cu, , 2, , 2, , (aq ) ||, , , Ag, , (b), , Pt| Cu || Ag, , (c), , Cu 2 | Cu || Pt | Ag, , , , (aq ) |, , Ag(s), , (d) 540.48 ohm 1 cm 2 mol 1, 33., , (d) None of the above representations, 24., , Zn(s) | Zn 2 (aq ) | | Cu 2 (aq ) | Cu (s) is, (anode), , 25., , (b) Daniel cell, (d) Faraday cell, , 1, , (b) 0 cm, , 1, , 27., , 34., , The specific conductance of a solution is 0.2 ohm 1cm 1 and, conductivity is 0.04 ohm 1 . The cell constant would be, (a) 1 cm, , 26., , [Kerala (Engg.) 2002], , (cathode), , (a) Weston cell, (c) Calomel cell, (e) Standard cell, , (b), , Pb(s)  SO 42  (aq) ⇌ PbSO 4 (s)  2e , , (c), , PbO2 (s)  4 H  (aq)  2e   SO 42 (aq) ⇌, [RPET 1999], , (d), , 1, , 35., , 36., , Pb 2 (aq)  SO 42 (aq)  PbSO 4 (s), , ohm, , 1, , cm, , 1, , [MP PET 1996], , (b) ohm cm, , (c) cm, (d) cm 1, In dry cell, reaction, which takes place at the zinc anode is, [IIT the, Screening, 2002], [MP PET 1996], , (b) Velocity of NO 3 is greater than that of K , (c) Velocities of both K  and NO 3 are nearly the same, KNO 3 is highly soluble in water, , In balancing the half reaction S 2 O32   S (s) the number of, electrons that must be added is, [DPMT 2000], (a) 4 on the left, (b) 3 on the right, (c) 2 on the left, (d) 2 on the right, , PbSO 4 (s)  2 H 2 O, , The unit of cell constant is, (a), , (a) Velocity of K  is greater than that of NO 3, , 28., , cm 1 ) is, (a) 4  3, (b) 4 / 3, (c) 3 / 4, (d) 9 / 4, The anode half-reaction occurring during the discharge of a lead, storage battery is, (a) Pb(s)  SO 2  O 2  PbSO 4 (s), , 1, , (c) 5 cm, (d) 0.2 cm, If the conductance and specific conductance of a solution is one, then its cell constant would be [RPET 1999], (a) 1, (b) Zero, (c) 0.5, (d) 4, Saturated solution of KNO 3 is used to make ‘salt-bridge’ because, , (d), , The electrodes of a conductivity cell are 3 cm apart and have a, cross-sectional area of 4 cm 2 . The cell constant of the cell (in, , (aq ) | Ag(s), , 37., , 2, , , ,  2e  Zn(s), , (a), , Zn, , (b), , Zn(s)  Zn 2   2e , , (c), , Mn2   2e   Mn(s), , (d), , Mn(s)  Mn  e   1.5 V, , The chemical reaction taking place at the anode of a cell is, [MP PET 1996], , (a) Ionisation, , (b) Reduction

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Electrochemistry, , 38., , (c) Oxidation, (d) Hydrolysis, Which of the following reactions occurs at the cathode during the, charging of a lead storage battery, [Manipal MEE 1995; MP PET 2002], , (a), (b), (c), (d), 39., , 40., , Pb, , Pb, , 2, , 2, , , , Pb  Pb, , 2, ,  PbSO4, ,  2e, , HCl  203 ohm 1 cm 2 gmeq 1 ,, , , , PbSO4  2 H 2 O  2 PbO2 , , 4 SO 42 , ,  2e, , What is the value of ClCH 2 COOH, , , , SO 2 is evolved, , (b) Lead sulphate is consumed, (c) Lead is formed, (d) Sulphuric acid is consumed, In electroplating, the article to be electroplated serves as, [AMU 1982, 83], , (a) Cathode, (b) Electrolyte, (c) Anode, (d) Conductor, The position of some metals in the electrochemical series in, decreasing, electropositive, character, is, given, as, Mg  Al  Zn  Cu  Ag. What will happen, if a copper spoon, is used to stir a solution of aluminium nitrate, , 50., , 51., , 45., , 46., , 52., , 289.5 ohm 1 cm 2 gmeq 1, , (c), , 388.5 ohm 1 cm 2 gmeq 1, , Which of the following statement is true for the electrochemical, Daniel cell, [AIIMS 2004], (a) Electrons flow from copper electrode to zinc electrode, (b) Current flows from zinc electrode to copper electrode, (c) Cations move toward copper electrode which is cathode, (d) Cations move toward zinc electrode, Which of the following statement is true for an electrochemical cell, (a) H 2 is cathode and Cu is anode, H 2 is anode and Cu is cathode, , (c) Reduction occurs at H 2 electrode, (d) Oxidation occurs at Cu electrode, Which of the following statements are true for an fuel cells, [DPMT 2004], , (a) They run till the reactants are active, (b) They are free from pollution, (c) They are more efficient, (d) All of the above, For gold plating, the electrolyte used is [Pb.CET 2004], , [MP PET 2003], , CH 3 COOK, , (b), , KCl, , (c) NH 4 NO 3, (d) KNO 3, The reference electrode is made by using, (a) ZnCl 2, (b) CuSO 4, (c), , 48., , (b), , (b) An alloy of Cu and Al is formed, (c) The solution becomes blue, 53., (d) There is no reaction, In a electrochemical cell, [AFMC 1989], (a) AuCl 3, (b) HAuCl4, (a) Potential energy changes into kinetic energy, (c) k[ Au(CN )2 ], (d) None of these, (b) Kinetic energy changes into potential energy, (c) Chemical energy changes into electrical energy, 54., The acid used in lead storage battery is [Pb.CET 2003], (d) Electrical energy changes into chemical energy, (a) H 2 SO 4, (b) H 3 PO4, In galvanic cell, the salt bridge is used to, [MP PMT 2002], (a) Complete the circuit, (c) HCl, (d) HNO 3, (b) Reduce the electric resistance in the cell, 55., At 25°C specific conductivity of a normal solution of KCl is, (c) Separate cathode from anode, 0.002765 mho. The resistance of cell is 400 ohms. The cell constant, (d) Carry salts for the chemical reaction, is, [Pb.PMT 2004], If a strip of Cu metal is placed in a solution of ferrous sulphate[NCERT 1974; CPMT, 1977; MP PET 2000], (a) 0.815, (b) 1.016, (a) Copper will precipitate out, (c), 1.106, (d) 2.016, (b) Iron will precipitate out, 56., Which of the following is used widely in the manufacture of lead, (c) Copper will dissolve, storage battery, [BHU 2004], (d) No reaction will take place, Which of the following is not used to construct salt bridge, (a) Arsenic, (b) Lithium, (a), , 47., , 288.5 ohm 1 cm 2 gmeq 1, , (b), , (a) The spoon will get coated with Al, , 44., , (a), , [JEE Orissa 2004], , (d) 59.5 ohm 1 cm 2 gmeq 1, , [NCERT 1977], , 43., , ClCH 2COONa  224 ohm 1 cm 2 gmeq 1 ,,  NaCl  38.2 ohm 1 cm 2 gmeq 1 ,, , A depolarizer used in dry cell batteries is, [NCERT 1981], (a) Ammonium chloride, (b) Manganese dioxide, (c) Potassium hydroxide, (d) Sodium phosphate, When a lead storage battery is discharged, (a), , 42., , 49., ,  2e  Pb, , [IIT 1987; MP PMT 2004], , 41., , (b) Create potential difference between the two electrodes, (c) Generate heat, (d) Remove adsorbed oxygen from electrode surfaces, , , , SO 42 , , 515, , HgCl2, , (d), , (c) Bismuth, 57., , [MP PMT 2002], , The, , reaction,, , 2 AgCl(s)  H 2 (g) , , 2 HCl(aq)  2 Ag(s) taking place in a galvanic cell is represented, by the notation, [AIIMS 2005], , (a), , Pt| H 2 (g),1bar | 1M KCl(aq)|AgCl(s)| Ag(s), , (b), , , Pt[AIEEE, (s)| H2004], 2 (g), 1bar | 1M HCl(aq)|| 1M Ag (aq)| Ag(s), , Hg2 Cl 2, , In a hydrogen – oxygen fuel cell, combustion of hydrogen occurs to, (a) Produce high purity water, , chemical, , (d) Antimony

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516 Electrochemistry, , 58., , (c), , Pt(s)| H 2 (g), 1bar | 1M HCl(aq)| AgCl(s)| Ag(s), , (d), , Pt(s)| H 2 (g), 1bar | 1M HCl(aq)| Ag(s)| AgCl(s), , If the Zn 2 / Zn electrode is diluted to 100 times then the change, in e.m.f., [DPMT 2005], , 5., , (a), , (a) Increase of 59 mV, 6., , (b) Decrease of 59 mV, (c) Increase of 29.5 mV, (d) Decrease of 29.5 mV, 59., , 60., , The tendency of an electrode to lose electrons is known as, [J & K 2005], , 7., , (b) Reduction potential, , (c) Oxidation potential, (d) e.m.f., When electric current is supplied through an ionic hydride of fused, state, then, [Kerala CET 2005], (a) Hydrogen is obtained at anode, (b) Hydrogen is obtained at cathode, (c) No change, (d) Hydride ion moves towards cathode, (e) hydride ion present in solution, , 8., , Zn 2  / Zn and Ag  / Ag, respectively. The standard, , B  0.136 V, , C  0.126 V, , D  0.402 V, , The element that displaces A from its compounds is, (a) B, (b) C, (c) D, (d) None of these, The standard oxidation potential of zinc and silver in water at, 298 K are, , Which of the following reactions actually take place, [NCERT 1983, 84; KCET 2003], , 9., , [KCET 1993], , 0.036 V, 0.799 V, 298 K for the following half, , Zn 2  (aq.)  2e ⇌ Zn(s) ;, , – 0.762, , Cr 3  (aq)  3e ⇌ Cr(s) ;, , – 0.740, , 2 H  (aq)  2e ⇌ H 2 (g) ;, , 0.00, , 3, , (c), , Zn(s), , H 2 (g ), , (d), , (a), , Zn(s)  2 Ag (aq)  Zn (aq)  2 Ag(s), , (b), , Zn   (aq)  2 Ag(s)  2 Ag  (aq)  Zn(s), , (c), , Zn(s)  Ag(s)  Zn   (aq)  Ag  (aq), , (d), , Zn   (aq)  Ag  (aq)  Zn(s)  Ag(s), , Beryllium is placed above magnesium in the second group. Beryllium, dust, therefore when added to MgCl2 solution will, [CPMT 1977], , (b) Precipitate Mg metal, , 10., , 2, , (b), , , , (c) Precipitate MgO, , [IIT 1981; MP PET/PMT 1988; MP PMT 1989;, MH CET 2001], , (a), , , , (a) Have no effect, , Fe (aq)  e ⇌ Fe (aq) ;, 0.770, Which is the strongest reducing agent, , 4., , A  0.250 V, , Ag (s)  Ag 2   2e  ; E  0.80 V, , 25 C . The potential of the cell would be (the value of, [KCET 1993,2005], 2.303 RT / F is 0.059 V), (a) 0.177 V, (b) – 0.177 V, (c) 0.087 V, (d) 0.059 V, , 3., , The standard reduction electrode potentials of four elements are, , The hydrogen electrode is dipped in a solution of pH  3 at, , The standard electrode potentials of, are  0.763 V and  0.799 V, potential of the cell is, (a) 1.56 V, (b), (c) – 1.562 V, (d), The standard reduction potentials at, reactions are given against each, , (d) Cu, Hg, Ag, , Ag, Hg, Cu, , Zn (s)  Zn 2   2e  ; E  0.76 V, , o, , 2., , Fe, , (c) Zn, (d) Ag, A solution containing one mole per litre of each, Cu(NO 3 )2 , AgNO3 , Hg2 (NO 3 )2 and Mg(NO 3 )2 , is being, electrolysed by using inert electrodes. The values of standard, electrode potentials in volts (reduction potentials) are, , (c), , Electrode potential, ECell, Nernt equation and ECS, 1., , (b), , Mg, , Ag / Ag   0.80, 2 Hg / Hg 22  0.79, Cu / Cu 2  0.34,, If hydrogen electrode dipped in 2 solution of pH  3 and, Mg / Mg 2   2.37 with increasing voltage, the sequence of, pH  6 and salt bridge is connected the e.m.f. of resulting cell is [DPMT 2005], deposition of metals on the cathode will be, (a) 0.177 V, (b) 0.3 V, [IIT 1984; AMU 1999; Kerala PMT 2004], (a) Ag, Hg, Cu, Mg, (b) Mg, Cu, Hg, Ag, (c) 0.052 V, (d) 0.104 V, , (a) Electrode potential, 61., , [CPMT 1999], (a) > copper, (b) < copper, (c) > sulphate, (d) < sulphate, Which of the following metal does not react with the solution of, copper sulphate, [CPMT 1999], , Cr(s), 2, , 11., , (d) Lead to dissolution of Be metal, The name of equation showing relation between electrode potential, (E) standard electrode potential (E o ) and concentration of ions in, solution is, (a) Kohlrausch's equation, (b) Nernst's equation, (c) Ohm's equation, (d) Faraday's equation, The correct representation of Nernst's equation is, (a), , E M n / M  E o M n / M , , 0.0591, log(M n  ), n, , (b), , E M n / M  E o M n / M , , 0.0591, log(M n  ), n, , Fe (aq), , When Zn piece is kept in CuSO 4 solution, the copper get, precipitated due to standard potential of zinc is

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Electrochemistry, (c), , E M n / M  E o M n / M , , n, log(M n  ), 0.0591, , 20., , (d) None of the above, 12., , 13., , Standard electrode potential of NHE at 298 K is, (a) 0.05 V, (b) 0.1 V, (c) 0.00 V, (d) 0.11 V, When a copper wire is placed in a solution of AgNO3 , the solution, acquires blue colour. This is due to the formation of, , 21., , [Roorkee 1989], , (a), (b), , 2, , Cu, Cu, , , , ions, 22., , ions, , (c) Soluble complex of copper with AgNO3, (d), 14., , Cu  ion by the reduction of Cu, , Consider, , the, , reaction, , M (naq ), , , ,  ne  M (s) ., , The, , standard, , 23., , reduction potential values of the elements M1 , M 2 and M 3 are, 0.34 V,  3.05 V and 1.66 V respectively. The order of their, reducing power will be, [NCERT 1990], , 15., , (a), , M1  M 2  M 3, , (b), , M 3  M 2  M1, , (c), , M1  M 3  M 2, , (d), , M 2  M 3  M1, , (a) A, (b) B, (c) C, (d) D, Which one of the following metals cannot evolve H 2 from acids or, , 25., , 26., , [MP PET/PMT 1988; CPMT 1996;, AFMC 1998, 99; Pb. PET 1999; BVP 2003], , 18., , (b), , 27., , 2 H  (aq)  2e   H 2 (g). The standard electrode potential for, the above reaction is (in volts), [CPMT 1988], (a) 0, (b) + 1, (c) – 1, (d) None of these, K, Ca and Li metals may be arranged in the decreasing order of, their standard electrode potentials as [CPMT 1990], (a) K, Ca, Li, (b) Ca, K, Li, , (c) Li, Ca, K, (d) Ca, Li, K, The correct order of chemical reactivity with water according to, electrochemical series, [MP PMT 1991], (a) K  Mg  Zn  Cu, (b) Mg  Zn  Cu  K, , EMF of cell Ni | Ni, , 2, , Al, , (1.0 M ) || Au 3  (1.0 M ) | Au (Where, , Fe  H 2 SO 4  FeSO 4  H 2, , (b), , Cu  2 AgNO3  Cu (NO 3 )2  2 Ag, , (c), , 2 KBr  I2  2 KI  Br2, , (d), , CuO  H 2  Cu  H 2 O, , [MP PET 1993; MP PMT 2000], , (b), ,  1.75 V, , (c) + 1.75 V, (d) + 4.0 V, Oxidation and reduction take place in a cell, then its electromotive, force will be, [RPET 1999], (a) Positive, (b) Negative, (c) Zero, (d) Stable, For a spontaneous reaction the G, equilibrium constant (K) and, [AIEEE 2005], , (a) ve ,  1,  ve, , (b), , ve ,  1,  ve, , (c) ve ,  1,  ve, , (d), , ve ,  1,  ve, , The reference electrode is made from which of the following, (a), , ZnCl 2, , (b) CuSO 4, , (c), , Hg 2 Cl 2, , (d), , HgCl2, , 28., , The charge over anode in a galvanic cell is, (a) Negative, (b) Positive, (c) No charge, (d) Sometimes negative and sometimes positive, , 29., , The standard electrode potential for the two electrode A  / A and, , (c) Pb, (d) Fe, Which one of the following reaction is not possible, (a), , (d) Cu  Zn  Mg  K, , [MP PET/PMT 1988], , [MP PMT 1991], , 19., , Zn 2  is a reducing agent, , o, will be respectively, E Cell, , H 2 O or from its compounds, , Hg, , (d), , (a) + 1.25 V, , (a) Gibb's equation, (b) Gibb's–Helmholtz equation, (c) Nernst's equation, (d) Vander Waal's equation, Four alkali metals A, B, C and D are having respectively standard, electrode potential as –3.05,–1.66,–0.40 and 0.80. Which one will be, the most reactive, , (a), , Zn can't replace hydrogen from acids, Zn is a reducing agent, Zn is a oxidising agent, , 1.50 V ) is, , RT, E , In K eq . This is called, nF, 0, , [MP PMT/PET 1988 ; CPMT 1983;, MNR 1993; UPSEAT 2002], , 17., , (a), (b), (c), , E o for Ni 2  | Ni is  0.25 V; E o for Au 3 | Au is, , [CPMT 1988; MP PET 2000], , 16., , The reaction Zn 2   2e   Zn has a standard potential of, [KCET 1992], 0.76 V . This means, , (c) K  Zn  Mg  Cu, 24., , 517, , When a rod of metal A is dipped in an aqueous solution of metal, B (concentration of B 2  ion being 1M) at 25 o C , the standard, 30., electrode potentials are A 2  / A =–0.76 volts, B 2  /B = + 0.34 volts[KCET 1992], (a) A will gradually dissolve, (b) B will deposit on A, (c) No reaction will occur, (d) Water will decompose into H 2 and O 2, , B  / B are respectively 0.5 V and 0.75 V . The emf of the given, , cell A | A  (a  1) || B  (a  1) | B will be, (a) 1.25 V, (c) – 0.25 V, , (b) – 1.25 V, (d) 0.25 V, , The standard reduction potential for Li  / Li ; Zn 2  / Zn ;, H  / H 2 and Ag  / Ag is 3.05,  0.762, 0.00 and, 0.80 V . Which of the following has highest reducing capacity, , (a), , Ag, , (b), , H2, , (c), , Zn, , (d), , Li

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518 Electrochemistry, 31., , Fe   2e   Fe ; E o  0.440 V, , If an iron rod is dipped in CuSO 4 solution, [MADT Bihar 1984], , 32., , (a), (b), (c), (d), (e), , Blue colour of the solution turns green, Brown layer is deposited on iron rod, No change occurs in the colour of the solution, Blue colour of the solution vanishes, None of the above, , Eo, , values of Mg 2  / Mg is 2.37 V , of, , Fe    3e   Fe ; E o  0.036 V, The standard electrode potential (E o ) for, , Zn 2  / Zn, , is, , 40., , 2, , 0.76 V and Fe / Fe is 0.44 V . Which of the following, statements is correct, [EAMCET 1989], , 33., , 34., , (a), , Zn will reduce Fe 2 , , (b), , Zn will reduce Mg 2 , , (c), , Mg oxidises Fe, , (d), , Zn oxidises Fe, , [AIIMS 1982], , (b) – 0.404 V, (d) + 0.771 V, four elements, P, Q, R, S, , 41., , (c) R  Q  S  P, (d) P  S  Q  R, Which of the following metal can deposit copper from copper, sulphate solution, [CPMT 1983; MP PMT 1989], (a) Mercury, (b) Iron, (c) Gold, (d) Platinum, , The standard reduction potential for Fe 2  / Fe and Sn 2 / Sn, 42., Standard electrode potential of Ag  / Ag and Cu  / Cu is, electrodes are 0.44 and 0.14 volt respectively. For the given cell, 0.80 V and 0.34 V respectively. these electrodes are joint, reaction Fe 2   Sn  Fe  Sn 2  , the standard EMF is[IIT Screening 1990; MP PMT, 2003] by salt bridge if, together, [AMU 2002], (a) + 0.30 V, (b) – 0.58 V, o, (a) Copper electrode is work like cathode, then E cell is 0.45 V, (c) + 0.58 V, (d) – 0.30 V, o, (b) Silver electrode is work like anode then E cell, is 0.34 V, Electrode potential of Zn 2  / Zn is 0.76 V and that of, o, (c) Copper electrode is work like anode then E cell, is 0.46 V, o, (d) Silver electrode is work like cathode then E cell, is 0.34 V, , [EAMCET 1992; BHU 2001; CBSE PMT 2001; KCET 1990;, MHCET 1999, 2003; Pb. CET 2002;, AFMC 2001; Pb. PMT 2004], , (a) 1.10 V, (b) 0.42 V, (c) – 1.1V, (d) – 0.42 V, EMF of a cell whose half cells are given below is, , Mg, Cu, , 2, , 2, , (e) Silver electrode is work like anode then, , o, will be, E cell, , 43., , 1.14 V, The reaction is spontaneous if the cell potential is, , 44., , (a) Positive, (b) Negative, (c) Zero, (d) Infinite, Which substance eliminates bromine from KBr solution, , [MP PET 1999], , , ,  2e  Mg(s); E  2.37 V,  2e   Cu(s); E  0.33 V, [EAMCET 1987; MP PET 1994; Pb. PMT 2000], , 36., , 37., , (a) – 2.03 V, (b) 1.36 V, (c) 2.7 V, (d) 2.03 V, A cell constructed by coupling a standard copper electrode and a, standard magnesium electrode has emf of 2.7 volts. If the standard, reduction potential of copper electrode is + 0.34 volt that of, magnesium electrode is, [KCET 1989], (a) + 3.04 volts, (b) – 3.04 volts, (c) + 2.36 volts, (d) – 2.36 volts, o,  0.76 volt, which of, When E oAg  / Ag  0.8 volt and E Zn, 2, / Zn, , the following is correct, (a), , Ag  can be reduced by H 2, , (b), , Ag can oxidise H 2 into H , , (c), 38., , Zn, , 2, , [IIT 1981], , 45., , 46., , [MP PMT 1994], , (a), , I2, , (b) Cl 2, , (c), , HI, , (d), , SO 2, , A standard hydrogen electrode has zero electrode potential because[IIT 1997], (a) Hydrogen is easiest to oxidise, (b) The electrode potential is assumed to be zero, (c) Hydrogen atom has only one electron, (d) Hydrogen is the lightest element, In the electrochemical cell, H 2 (g)1 atm| H  (1M )|| Cu 2 (1M )| Cu(s), , Which one of the following statements is true, [EAMCET 1997], , (a), , can be reduced by H 2, , (a) More iron and Pb 2  ions are formed, , (d), , H 2 is anode; Cu is cathode, , 47., , Expression representing the cell potential (E cell), , 48., , (a) E + E, (b) E – E, (c) E – E, (d) E – E, Iron displaces copper from its salt solution, because, , (b) More lead and Fe 2  ions are formed, (c) Concentration of both Pb 2  and Fe 2  ions increases, (d) There is no net change, Given standard electrode potentials, , H 2 is cathode; Cu is anode, , (b) Oxidation occurs at Cu electrode, (c) Reduction occurs at H 2 electrode, , (d) Ag can reduce Zn 2  ion, Adding powdered lead and iron to a solution that is 1.0 M in both, Pb 2  and Fe 2  ions, would result a reaction, in which, [CPMT 1987], , 39., , is, ,  2.90,  0.34,  1.20 and  0.76. Reactivity decreases in the, order, [MP PET 1989; UPSEAT 2001], (a) P  Q  R  S, (b) Q  P  R  S, , Cu 2  / Cu is 0.34 V . The EMF of the cell constructed between, these two electrodes is, , 35., , Fe    e   Fe  is, (a) – 0.476 V, (c) + 0.404 V, Reduction potential of, , cathode, , cathode, , anode, , anode, , anode, , left, , cathode, , right, , [MP PMT 1996], , (a) Atomic number of iron is less than that of copper

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Electrochemistry, , 49., , 50., , 51., , 52., , (b) The standard reduction potential of iron is less than that of, copper, (c) The standard reduction potential of iron is more than that of, copper, (d) The iron salt is more soluble in water than the copper salt, (i) Copper metal dissolves in 1M silver nitrate solution and crystals, of silver metal get deposited., (ii) Silver metal does not react with 1 M zinc nitrate solution, (iii) Zinc metal dissolves in 1M copper sulphate solution and, copper metal gets deposited, Hence the order of decreasing strength of the three metals as, reducing agents will be, (a), , Cu  Ag  Zn, , (b), , Ag  Cu  Zn, , (c), , Zn  Cu  Ag, , (d), , Cu  Zn  Ag, , Standard electrode potentials of Zn and Fe are known to be (i), 0.76 V and (ii) 0.44 V respectively. How does it explain that, galvanization prevents rusting of iron while zinc slowly dissolves, away, (a) Since (i) is less than (ii), zinc becomes the cathode and iron, the anode, (b) Since (i) is less than (ii), zinc becomes the anode and iron the, cathode, (c) Since (i) is more than (ii), zinc becomes the anode and iron the, cathode, (d) Since (i) is more than (ii), zinc becomes the cathode and iron, the anode, Amongst the following electrodes the one with zero electrode, potential is, [MP PMT 1997], (a) Calomel electrode, (b) Standard hydrogen electrode, (c) Glass electrode, (d) Gas electrode, Which of the following is correct expression for electrode potential, of a cell, [MP PMT 1997], (a) E  E o , , 53., , 54., , 55., , RT [product], ln, nF [reactant], , (b) E  E o , , RT [product], ln, F, [reactant], , (c) E  E o , , RT [reactant], ln, nF [product], , RT [product], ln, (d) E  , F, [reactant], Calculate standard free energy change for the reaction, 1, 1, 1, Cu (s)  Cl 2 (g) ⇌ Cu 2   Cl  taking place at 25 o C in a, 2, 2, 2, cell whose standard e.m.f. is 1.02 volts [MP PMT 1997], (a) – 98430 J, (b) 98430 J, (c) 96500 J, (d) – 49215 J, In which cell the free energy of a chemical reaction is directly, converted into electricity ?, [MP PET/PMT 1998], (a) Leclanche cell, (b) Concentration cell, (c) Fuel cell, (d) Lead storage battery, Nernst equation is related with, (a) The electrode potential and concentration of ions in the, solution, (b) Equilibrium constant and concentration of ions, (c) Free energy change and E.M.F. of the cell, (d) None of these, , 56., , 519, , The standard reduction potentials of 4 elements are given below., Which of the following will be the most suitable reducing agent, I = – 3.04 V, II = – 1.90 V, III = 0 V, IV = 1.90 V, [CPMT 1999], , 57., , (a) I, (b) II, (c) III, (d) IV, Electrode potential data are given below :, , Fe 3  (aq)  e   Fe 1 (aq); E o  0.77 V, Al 3  (aq)  3e   Al(s); E o  1.66 V, Br2 (aq)  2e   2 Br  (aq); E o  1.08 V, , Based on the data given above, reducing power of Fe 2 , Al and, Br  will increase in the order, , 58., , 59., , 60., , Br   Fe 2  Al, , (b), , Fe 2  Al  Br , , (c), , Al  Br   Fe 2, , (d), , Al  Fe 2  Br , , The standard electrode potential (E o ) for OCl  / Cl  and, 1, Cl  / Cl 2 respectively are 0.94 V and 1.36 V . The E o, 2, 1, value for OCl  / Cl 2 will be, [KCET 1996], 2, (a) 0.42 V, (b)  2.20 V, (c) 0.52 V, (d) 1.04 V, If the reduction potential is more, then, (a) It is easily oxidised, (b) It is easily reduced, (c) It acts as oxidising agent, (d) It has redox nature, One of the following is false for Hg [BHU 1998], (a), (b), (c), (d), , 61., , [Pb. PMT 1998], , (a), , [CPMT 1996], , It can evolve hydrogen from H 2 S, It is a metal, It has high specific heat, It is less reactive than hydrogen, , E o for the cell Zn | Zn 2 (aq)|| Cu 2 (aq)| Cu is 1.10 V at, , 25 o C , the equilibrium constant for the, Zn  Cu 2 (aq) ⇌ Cu  Zn 2 (aq) is of the order of, , reaction, , [CBSE PMT 1997], , (a), (c), 62., , 10, 10, , 28, 18, , (b) 10, , 37, , (d) 10 17, , Standard, reduction, potentials, , 2, , and, Li | Li, Ba | Ba, Na | Na, , at, 25 o C, Mg 2 | Mg, , of, are, , 3.05,  2.90,  2.71 and 2.37 volt respectively. Which one of, the following is the strongest oxidising agent, [CBSE PMT 1994; JIPMER 2002], , 63., , (a), , Na , , (b), , Li , , (c), , Ba 2 , , (d), , Mg 2 , , Which of the following displaces Br2 from an aqueous solution, containing bromide ions, [CBSE PMT 1994; JIPMER (Med.) 2002], , 64., , (a), , Cl 2, , (b) Cl , , (c), , I2, , (d), , I 3, , For the cell reaction, Cu 2 (C1 aq)  Zn(s)  Zn 2 (C 2 aq)  Cu(s)

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520 Electrochemistry, of an electrochemical cell, the change in free energy at a given, temperature is a function of, [CBSE PMT 1998], (a) ln (C1 ), (b) ln (C 2 ), 65., , (c) ln (C1  C 2 ), , (d) ln (C 2 / C1 ), , The e.m.f. of the cell in, , which the following reaction, , (c) – 0.19 V, 74., , Fe, , RT, , , o, is 1.10 volt. Ecell for the cell will be  2 .303,  0 .0591, Ecell, F, , , , (a), (c), 75., , 76., , [AIEEE 2003], , 67., , (a) 2.14 volt, (c) 1.07 volt, The, emf of, , a, , (b) 1.80 volt, (d) 0.82 volt, Daniel, cell, at, 298K, , is, , is 1.0 M and that of CuSO 4 is 0.01 M the emf changed to E 2 . What, ,, , 77., , 68., , E1  E2, , (c), , E1  E2, , (d), , E1  E2, , (a), , MX M  X, , , , , is the spontaneous reaction, , , , Fe  Fe2   2e  ; E o  0.44 V what will be the emf of cell,, , (d), , Ecell = – 0.77 V, , 2, , 78., , (b) + 0.32 V, (d) + 1.20 V, , (a), , Cu 2  oxidises Fe, , (b), , Cu 2  oxidises Fe 2 , , (c), , Cu oxidises Fe 2 , , (d), , Cu reduces Fe 2 , , o, , What, is, for, E, Pt, O 2 (1 atm) / 2 H  (Im), , electrode, , represented, , When zinc dust is added to the solution of MgCl2, [UPSEAT 2001], , (a), , (b), , by, 79., , 80., , Hg, , The emf of the cell Fe 2   Zn  Zn 2   Fe is, [CPMT 2003], , reduced to MnO2 The equivalent weight of KMnO4 in neutral, medium, [AMU 2001], (a) mol. wt/2, (b) mol.wt/3, (c) mol. wt/4, (d) mol .wt/7, Which of the following condition will increase the voltage of the cell,, represented, by, the, equation, Cu (s)  2 Ag (aq )  Cu 2 (aq )  2 Ag(s), [CBSE PMT 2001], (a) Increase in the concentration of Ag  ion, , Fe 2   2e   Fe; E  7.81 V, , (b) – 1.54 V, , KMnO4 acts as an oxidising agent in the neutral medium and gets, ., , (c) Zn, (d) Na, The standard electrode potential of the half cells are given below, Zn 2   2e   Zn; E  7.62 V,, , (a) 1.54 V, , ZnCl 2 is formed, , (b) Zinc dissolves in the solution, (c) No reaction takes place, (d) Mg is precipitated, , [JIPMER 1997], , (a) Unpredictable, (b) Zero, (c) 0.018 V, (d) 0.118 V, The cell potential of a cell in operation is, (a) Zero, (b) Positive, (c) Negative, (d) None of the above, Which of the following is displaced by Fe, [Roorkee 1995], Ag, , The standard potential at 25 o C for the following half reactions are, given against them, Zn 2   2e  Zn, E o  0.762V, , Mg 2   2e  Mg, E o  2.37 V, , The E o for half cells Fe / Fe2  and Cu / Cu 2  are – 0.44 V and, + 0.32 V respectively. Then, [MP PMT 2003], , (a), 73., , , , M  X  M  X is the spontaneous reaction, Ecell = 0.77 V, , [MP PMT 2003], , 72., , (d) 1  1010, , (c) 10, For the electrochemical cell,, , (b), (c), , (a) – 1.20 V, (c) – 0.32 V, , 71., , 29.5  10 2, , [IIT-JEE (Screening) 2000], , whose cell-reaction is Fe (aq)  Zn  Zn (aq)  Fe, , 70., , (b), , The oxidation potentials of following half-cell reactions are given, Zn  Zn 2   2e  ; E o  0.76 V ,, 2, , 69., , 1  10, , 10, , M | M  || X  | X , E o (M  / M ) = 0.44 V and E o (X / X  ) =, 0.33 V. From this data one can deduce that, , [CBSE PMT 2003], , (b), , (b) Zn, Fe, (d) H 2, Cr, Standard reduction electrode potentials of three metals A, B and C are, respectively + 0.5V, – 3.0V and – 1.2 V. The reducing powers of these, metals are, [IIT 1998; AIEEE 2003], (a) B > C > A, (b) A > B > C, (c) C > B > A, (d) A > C > B, For a cell reaction involving a two-electron change, the standard emf, of the cell is found to be 0.295 V at 25 o C . The equilibrium, , (a), , is the relationship between E1 and E 2, E2  0  E1, , [BHU 2003], , 2, , [Roorkee 1999; AIEEE 2003; CBSE PMT 2004], , E1, , (1.0 M ), , (a), ,  e   Fe2  ; E o   0.77 ,, , constant of the reaction at 25 o C will be, , Zn | ZnSO 4 || CuSO 4 | Cu when the concentration of ZnSO 4, (0.01 M ), ,  2e  Zn(s); E   0.76 ,, , 3, , o, , H   2e   1 / 2 H 2 ; E o  0.00, Strongest reducing agent is, , [Roorkee Qualifying 1998], , 66., , , , Cr 3   3e   Cr ; E o   0.79 ,, , Zn(s)  Ni 2 (a  1.0) ⇌ Zn 2  (a  10)  Ni(s) occurs, is found, to be 0.5105 V at 298K . The standard e.m.f. of the cell is, (a) 0.5400, (b) 0.4810 V, (c) 0.5696 V, (d) – 0.5105 V, For the redox reaction, Zn(s)  Cu 2  (0.1M )  Zn 2  (1M )  Cu(s) taking place in a cell,, , Zn, , (d) + 0.19 V, , 2, , 81., , (b) Increase in the concentration of Cu  ion, (c) Increase in the dimension of silver electrode, (d) Increase in the dimension of copper electrode, Which, will, increase, the, voltage, Sn(s)  2 Ag (aq)  Sn 2 (aq)  2 Ag(s), , of, , the, , cell, , [DPMT 2001]

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Electrochemistry, (a) Increase in the concentration of Ag  ions, , 82., , 91., , Which of the following has been universally accepted as a reference, electrode at all temperatures and has been assigned a value of zero, volt [AIIMS 1998], (a) Graphite electrode, (b) Copper electrode, (c) Platinum electrode, (d) Standard hydrogen electrode, , 92., , Aluminium is more reactive than Fe . But Al is less easily corroded, than iron because, [DCE 1999], (a) Al is noble metal, (b) Iron forms both mono and divalent ions, (c) Oxygen forms a protective oxide layer, , (b) Increase in the concentration of Sn 2  ions, (c) Increase in size of the silver rod, (d) None of these, The mass of the proton is 1840 times that of electron, its potential, difference is V. The kinetic energy of proton is, [DCE 2001], , (a) 1840 KeV, , (b) 1 KeV, , 1, KeV, (d) 920 KeV, 1840, What, will, be, the, emf, for, the, , Pt | H 2 (P1 )| H (aq ) || H 2 (P2 )| Pt, (c), , 83., , (a), (c), 84., , P, RT, log 1, f, P2, , (b), , P, RT, log 2, f, P1, , given, , cell, , [AIEEE 2002], , P, RT, log 1, 2f, P2, , (d) Fe undergoes reaction easily with H 2 O, 93., , Zinc displaces copper from the solution of its salt because, , 94., , (a) Atomic number of zinc is more than that of copper, (b) Zinc salt is more soluble in water than the copper salt, (c) Gibbs free energy of zinc is less than that of copper, (d) Zinc is placed higher than copper in electro-chemical series, An electrochemical cell is set up as follows, , [MP PET 1995], , (d) None of these, , What is the potential of a cell containing two hydrogen electrodes, the negative one in contact with 10 8 M H  and positive one in, contact with 0.025 M H , , Pt(H 2 , 1 atm) / 0.1 M HCl, , [MP PMT 2000], , (a) 0.18 V, (c) 0.38 V, 85., , 86., , 87., , 88., , Will Fe(s) be oxidised to Fe, , | 0.1 M acetic acid /( H 2 , 1 atm ) Pt, , (b) 0.28 V, (d) 0.48 V, 2, , E.M.F. of this cell will not be zero because, , by the reaction with 1 M HCl (E, , (a), , E  Eleft  Eright, , (b), , E  Eleft  Eright, , (c), , E  Eright  Eleft, , (d), , E  (Eright  Eleft), , [CBSE PMT 1995], , o, , for Fe / Fe2  = + 0.44 V), [Pb. PMT 2000], (a) Yes, (b) No, (c) May be, (d) Can’t say, EMF of a cell in terms of reduction potential of its left and right, electrodes is, [AIEEE 2002], , (a) The pH of 0.1 M HCl and 0.1 M acetic acid is not the same, (b) Acids used in two compartments are different, (c) E.M.F. of a cell depends on the molarities of acids used, (d) The temperature is constant, 95., , (a), , K, Ba, Ca, Mg, , (b), , Ca, Mg, K, Ba, , (c), , Ba, Ca, K, Mg, , (d), , Mg, Ca, Ba, K, , (a) – 0.49 V, (c) – 0.38 V, 96., , Which of the following has highest electrode potential, , 89., , (c) Au, The cell reaction of a cell is, , (b), , Cu, , (d), , Al, 97., , Mg(s)  Cu 2 (aq)  Cu (s)  Mg 2 (aq), If the standard reduction potentials of Mg and Cu are  2.37, [EAMCET 1995; JIPMER (Med.) 2001;, AFMC 2002; CBSE PMT 2002], , 90., , (a), , Cl, , (b), , F, , (c), , Br, , (d), , I, , (b) 0.49 V, (d) 0.38 V, , , , c, , d, , RT, [C] [D], log, nF, [ A]a [B]b, , (b), , [CPMT 1997], ,  RT log, , A, , [a] [b] B, [a]C [d ] D, , RT, [C]c [d ] D, RT, [C]c [d ] D, log a b, log A b, (d) , nF, nF, [ A] [ B], [a] [B], In the experiment set up for the measurement of EMF of a half cell, using a reference electrode and a salt bridge, when the salt bridge is, removed, the voltage, (c), , , , (a), (b), (c), (d), , Does not change, Decreases to half the value, Increase to maximum, Drops to zero, , [NCERT 1984; CPMT 1985], , and  0.34 V respectively. The emf of the cell is, , (a) 2.03 V, (b) – 2.03 V, (c) + 2.71 V, (d) – 2.71 V, The element which can displace three other halogens from their, compound is, [EAMCET 1998], , [IIT 1995], , E o of a cell aA  bB  cC  dD is, , (a), , [Pb. PMT 2000], , Li, , Cu  ion is not stable in aqueous solution because of, disproportionation reaction. E o value for disproportionation of, Cu  is, o, o,  0.15 , ECu,  0.34 V ), (Given ECu, 2, 2, / Cu , / Cu, , Arrange the following in the order of their decreasing electrode, potential Mg, K, Ba, Ca, [JIPMER 2002], , (a), , 521, , 98., , Electrode potentials of five elements A, B, C, D and E are, respectively – 1.36 , – 0.32, 0, – 1.26 and –0.42. The reactivity order, of these elements are in the order of, [MP PMT 1995], , 99., , (a) A, D, E, B and C, (b) C, B, E, D and A, (c) B, D, E, A and C, (d) C, A, E, D and B, What is wrongly stated about electrochemical series

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522 Electrochemistry, [DCE 1999], , 109., , (a) It is the representation of element in order of increasing or, decreasing standard electrode reductional potential, (b) It does not compare the relative reactivity of metals, (c) It compares relative strengths of oxidising agents, (d), 100., , [KCET (Med.) 1999; AFMC 2000], , 101., , ( F  96,500 C mol 1 ; R  8.314 JK 1mol 1 ) [AIEEE 2004], , H 2 is centrally placed element, , Which of the following statements is true for fuel cells, (a) They are more efficient, (b) They are free from pollution, (c) They run till reactants are active, (d) All of these, What is the potential of a half-cell consisting of zinc electrode in 0.01m, ZnSO 4 solution at 258 o C (E o  0.763 V ), , 110., , 102., , 103., , (a), 104., , (b) Au, Fe, (c) Hg, (d) Ag, The strongest reducing agent of the alkali metal is, , 111., , 112., , 107., , (b), , Al, , (c), , Na, , (d), , Au, , In a cell that utilises the reaction Zn(s)  2 H  (aq) , , Zn 2  (aq)  H 2(g) addition of H 2 SO 4 to cathode compartment,, will, [AIEEE 2004], (a) Increase the E and shift equilibrium to the right, (b) Lower the E and shift equilibrium to the right, (c) Lower the E and shift equilibrium to the left, (d) Increase the E and shift equilibrium to the left, 108., , For, , the, , electrochemical, , cell,, , (b), , 114., , (a) 3.66 V, (b) 0.80 V, (c) – 0.80 V, (d) – 3.66 V, The e.m.f. of a cell whose half cells are given below is, Mg 2   2e   Mg(s) E  2.37 V, [Pb.CET 2001], , (b) + 2.71 V, (d) – 3.01 V, , For the cell reaction, 2Ce 4   Co  2Ce 3   Co 2 , , M  X  M  X is the spontaneous reaction, , (d), , Ecell  .77 V, , [Pb.CET 2000], , (b) + 1.64 V, (d) + 2.17 V, , If the G of a cell reaction AgCl  e   Ag  Cl  is, [MP PMT 2004], 21.20 KJ ; the standard e.m.f., of cell is, (b) 0.220 V, (d) – 0.110 V, , The e.m.f. of the cell Ag | Ag  (0.1M )|| Ag  (1M )| Ag at 298 K, is, [DCE 2003], (a) 0.0059 V, (b) 0.059 V, (c) 5.9 V, (d) 0.59 V, , 116., , The e.m.f. of the cell Zn | Zn 2  (0.01M )|| Fe2  (0.001M )| Fe at, 298 K is 0.2905 then the value of equilibrium for the cell reaction is [IIT-JEE Scr, , 117., , M | M  || X  | X ,, , (c), , Ecell is, , 115., , (a), , 0 .32, e 0.0295, , (b), , 0 .32, 10 0.0295, , (c), , 0 .26, 10 0.0295, , (d), , 0 .32, 10 0.0591, , Aluminium displaces hydrogen from dilute HCl whereas silver does, not. The e.m.f. of a cell prepared by combining Al / Al3  and, , Ag / Ag  is 2.46 V. The reduction potential of silver electrode is, 0.80 V . The reduction potential of aluminium electrode is [KCET 2004], , M  X  M  X is the spontaneous reaction, , , (b) – 0.8 V, (d) 1.2 V, , A galvanic cell with electrode potential of ' A'  2.23 V and, , (a) 0.229 V, (c) – 0.220 V, , , , , , Standard electrode potential of cell H 2 | H  || Ag  | Ag is, , (a) – 1.64 V, (c) – 2.08 V, , Ecell  0.77 V, , , (d) 1.0  10 30, , (a) + 1.36 V, (c) + 2.17 V, , E(M  | M )  0.44 V E(X | X  )  0.33 V From this data, one, can deduce that, [Pb.CET 2004], , (a), , 1.0  101, , 1.89 V. If ECe 4  / Ce 3 , , (a) Carbon, (b) Calcium, (c) Chlorine, (d) Potassium, The metal that forms a self protecting film of oxide to prevent, corrosion, is, [BHU 1999], , Cu, , (c), , Cu 2   2e   Cu(s) E  0.34 V, , 113., , (a) Li, (b) Na, (c) K, (d) Cs, Which of the following is the most electropositive element, , (a), , (b) 1.0  10 5, , ' B'  1.43 V . The value of Ecell is [Pb.CET 2003], , [Pb. PMT 2000], , 106., , 1.0  1010, , [AIEEE 2004], , [CBSE PMT 2000], , 105., , (a), , (a) 0.8 V, (c) – 1.2 V, , [AIIMS 2000; BHU 2000], , (a) 0.8221 V, (b) 8.221 V, (c) 0.5282 V, (d) 9.232 V, The emf of a galvanic cell, with electrode potentials of silver = +0.80V, and that of copper = + 0.34 V, is, [AIIMS 1999], (a) – 1.1 V, (b) + 1.1 V, (c) + 0.46 V, (d) + 0.76 V, Copper cannot replace….. from solution [DPMT 2002], , The standard e.m.f. of a call, involving one electron change is found, to be 0.591 V at 25°C. The equilibrium constant of the reaction is, , 118., , (a), , 1.66 V, , (b), , 3.26 V, , (c), , 3.26 V, , (d), , 1.66 V, , Consider the following E 0 values :, , E 0 Fe 3  / Fe 2 = 0.77 V, , E 0 Sn 2 / Sn  0.14 V

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Electrochemistry, Under standard conditions the potential for the reaction, [AIEEE 2004], Sn (s)  2 Fe3  (aq)  2 Fe2  (sq)  Sn 2  (aq) is, , 119., , (a) 0.91 V, , (b) 1.40 V, , (c) 1.68 V, , (d) 0.63 V, , Cr2 O72   I   I2  Cr 3 , E, , 0, , cell, , 128., , 2, 2 O7, ,  1.33 V , E 0 I2 is, , [BVP 2004], , 0.10 V, , (b), , 0.18 V, , (c), , 0.54 V, , (d), , 0.54 V, , 129., , Zn(s)  Cl 2 (1 atm)  Zn 2   2Cl  . E 0 cell of the cell is 2.12 V., To increase E, [BVP 2004], , 1., , (b) [ Zn 2 ] should be decreased, , 121., , (c), , [Cl  ] should be decreased, , (d), , PCl 2 should be decreased, , The, , E, , M 3  / M 2, , values, , 2., for, , Cr, Mn, Fe and, , Co are, 3., , [AFMC 2005], , (c) Cr, (d) Co, The rusting of iron takes place as follows, , 4., , 2H +, + ½O  H O(l) ;, E° = +1.23 V, , (a), , 123., , 124., , (d), , HgCl2, , Fe is oxidised to Fe 2  and dissolved oxygen in water is, reduced to OH, , [IIT 2005], , (b), , Fe is oxidised to Fe 3  and H 2 O is reduced to O 22 , , (c), , Fe is oxidised to Fe 2  and H 2 O is reduced to O 2, , (d), , Fe is oxidised to Fe 2  and H 2 O is reduced to O 2, , 1, , 1, , PbCl2, , Hg2 Cl 2, , , , 2+, , 1, , FeCl2, , (b), , Corrosion of iron is essentially an electrochemical phenomenon, where the cell reactions are, [KCET 2005], , 2, , Fe + 2e  Fe(s) ; E° = 0.44 V, Calculate G° for the net process, (a) 322 kJ mol, (b) 161 kJ mol, , (c) 152 kJ mol, (d) 76 kJ mol, , (b) O 2, , Fe, , (c) Zn, (d) H , Which of the following is a highly corrosive salt, , (c), , 2, , [Kerala (Med.) 2002], , (b) Electrochemical phenomenon, (c) Interaction, (d) Union between light metal and heavy metal, Rusting of iron is catalysed by which of the following, , (b) Mn, , Fe, , 2e, , o, G o  nFEcell, , Corrosion is basically a, (a) Altered reaction in presence of H 2 O, , (a), , +, , (b), , [MNR 1990; UPSEAT 2001], , of these metals the change in oxidation state from 2 to 3 is, easiest, [AIEEE 2004], , 122., , o, G o  nFEcell, , o, (c) G o  2.303 RT nFEcell, (d) G o  nF log K C, For the feasibility of a redox reaction in a cell, the e.m.f. should be[J & K 2002], (a) Positive, (b) Fixed, (c) Zero, (d) Negative, , (a), , 0.41,  1.57,  0.77 and 1.97 V respectively. For which one, , (a), , [AMU 2002], , Corrosion, , [ Zn 2 ] should be increased, , 0, , E o Zn / Zn   is –0.74 volts, (a) 0. 38 volts, (b) 0.83 volts, (c) 0.40 volts, (d) 0.45 volts, Which of the following expression is correct, (a), , (a), , (a), , Calculate, the, electrode, potential, at, for, 298 o K, , Zn| Zn electrode in which the activity of zinc ions is 0.001 M and, , [Orissa JEE 2005], ,  0.79 V, , 0, ECr, , 120., , 127., , 523, , 1, , When an acid cell is charged, then, [AFMC 2005], (a) Voltage of cell increases, (b) Electrolyte of cell dilutes, (c) Resistance of cell increases, (d) None of these, The standard electrode potential is measured by, [KCET 2005], , 125., , (a) Electrometer, (b) Voltmeter, (c) Pyrometer, (d) Galvanometer, Aluminium displaces hydrogen from acids but copper does not. A, galvanic cell prepared by combining Cu / Cu 2  and Al / Al 3  has, an e.m.f. of 2.0 V at 298 K. If the potential of copper electrode is +, 0.34 V, that of aluminium is, , 1., , [CPMT 2001; KCET 2001], , (a) + 1.66 V, (c) + 2.34 V, 126., , (b) – 1.66 V, (d) – 2.3 V, , If the standard electrode potential of Cu 2 / Cu electrode is, 0.34V, what is the electrode potential of 0.01M concentration of, [EAMCET 2003], Cu 2  (T  298 K), (a) 0.399 V, (b) 0.281 V, (c) 0.222 V, (d) 0.176 V, , 2., , The limiting molar conductivities  0 for NaCl, KBr and KCl are 126,, 152 and 150 S cm 2 mol 1 respectively. The  0 for NaBr is, (a), , 278 S cm 2 mol 1, , (b) 176 S cm 2 mol 1, , (c), , 128 S cm 2 mol 1, , (d), , 302 S cm 2 mol 1, , On the basis of the electrochemical theory of aqueous corrosion, the, reaction occurring at the cathode is, [MP PET 1994; UPSEAT 2001], , (a), , O2 (g) , , 4 H (aq ), Fe(2aq ), , , ,  4 e  2 H 2 O(l),  2e , , (b), , Fe(s) , , (c), , Fe(2aq )  Fe(3aq )  e 

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524 Electrochemistry, (d), 3., , H 2(g)  2OH(aq )  2 H 2 O(l)  2e , , The reaction, , 1, 2, , (a) 5.49  107 C of electricity, (b) 1.83  10 7 C of electricity, , H 2 (g)  AgCl(s)  H  (aq)  Cl  (aq)  Ag(s), , (c) 5.49  10 4 C of electricity, , occurs in the galvanic cell, [IIT 1985; AMU 2002; KCET 2003], , 4., , (d) 5.49  101 C of electricity, , (a), , Ag / AgCl(s) KCl (soln) || AgNO3 (soln) / Ag, , (b), , Pt / H 2 (g) HCl (soln) || AgNO3 (soln) / Ag, , (c), , Pt / H 2 (g) HCl (soln) || AgCl (s) / Ag, , Calculate HOAc using appropriate molar conductances of the, , (d), , Pt / H 2 (g) KCl (soln) || AgCl (s) / Ag, , electrolytes listed above at infinite dilution in H 2 O at 25°C[AIEEE 2005], , 11., ,  (Scm mol, , , o, , The standard reduction potential E for the half reactions are as, Zn  Zn, , 2, , , ,  2e ; E  0.76 V, o, , 12., , Fe  Fe 2   2e  ; E o  0.41 V, , The EMF for cell reaction Fe 2   Zn  Zn 2   Fe is, [IIT 1988; CBSE PMT 1993, 96; BHU 1995, 2000;, CPMT 2000; KCET 2000; AIIMS 2001; Orissa JEE 2002], , 5., , (a), ,  0.35 V, , (b), ,  0.35 V, , (c), ,  1.17 V, , (d), ,  1.17 V, , 6., , 13., , 14., , (b) 4, (d) 2, , 2, , –1), , :, , KCl, , KNO3, , HCl, , NaOAc, , NaCl, , 149.9, , 145.0, , 426.2, , 91.0, , 126.5, , (a) 517.2, (b) 552.7, (c) 390.7, (d) 217.5, The mass of carbon anode consumed (giving only carbondioxide) in, the production of 270kg of aluminium metal from bauxite by the, Hall process is, [CBSE PMT 2005], (a) 180kg, (b) 270kg, (c) 540kg, (d) 90kg, 4.5g of aluminium (at mass 27amu) is deposited at cathode from, Al 3  solution by a certain quantity of electric charge. The volume, of hydrogen produced at STP from H  ions in solution by the, same quantity of electric charge will be, [CBSE PMT 2005], , The number of electrons to balance the following equation, [IIT Screening 1991], NO 3  4 H   e   2 H 2 O  NO is, (a) 5, (c) 3, , Electrolyte :, , (a) 22.4 L, (b) 44.8 L, (c) 5.6 L, (d) 11.2 L, What amount of Cl gas liberated at anode, if 1 amp. current is, passed for 30 min. from NaCl solution., 2, , [BHU 2005], , (a) 0.66 moles, (c) 0.66 g, , The standard, for the given cell reaction, EMF, 2, 2, is 1.10 V at 25 o C . The EMF for, Zn  Cu  Cu  Zn, the cell reaction, when 0.1M Cu 2  and 0.1M Zn 2  solutions are, , (b) 0.33 moles, (d) 0.33 g, , used, at 25 o C is, [MNR 1994; AMU 1999; UPSEAT 2002], , 7., , (a), , 1.10 V, , (b), , 0.110 V, , (c), , 1.10 V, , (d), ,  0.110 V, , A gas X at 1 atm is bubbled through a solution containing a, , (c), (d), (e), , If both assertion and reason are true and the reason is the correct, explanation of the assertion., If both assertion and reason are true but reason is not the correct, explanation of the assertion., If assertion is true but reason is false., If the assertion and reason both are false., If assertion is false but reason is true., , (d) Y will reduce both X and Z, The oxidation potential of a hydrogen electrode at pH = 10 and, [JIPMER 2000], pH 1  1, , 1., , Assertion, , :, , Reason, , :, , (a) 0.059 V, (b) 0.59 V, (c) 0.00 V, (d) 0.51 V, The decomposition of hydrogen peroxide is an example of, , 2., , Assertion, , :, , Reason, , :, , Assertion, , :, , Reason, , :, , Assertion, , :, , Reason, , :, , mixture of 1 M Y  and 1 M Z  at 25 o C . If the reduction, potential of Z  Y  X , then, , 8., , 9., , Read the assertion and reason carefully to mark the correct option out of, the options given below :, , (a), , Y will oxidize X and not Z, , (b), , Y will oxidize Z and not X, , (c), , Y will oxidize both X and Z, , [IIT 1999], , (a), (b), , [Roorkee 2000], , 10., , (a) Exothermic reaction, (b) Endothermic reaction, (c) Negative catalysis, (d) Auto-oxidation, Aluminium oxide may be electrolysed at 1000°C to furnish, aluminium metal (At. Mass = 27 amu; 1 Faraday = 96,500, Coulombs). The cathode reaction is, Al3  3e   Al, To prepare 5.12kg of aluminium metal by this method would, require, [AIEEE 2005], , 3., , 4., , Sodium ions are discharged in preference to, hydrogen ions at a mercury cathode., The nature of the cathode can effect the order of, discharge of ions., In electrolysis, the quantity of electricity needed, for depositing 1 mole of silver is different from, that required for 1 mole of copper., The molecular weights of silver and copper are, different, Equivalent conductance of all electrolytes, decreases with the increases in concentration., Lesser number of ions are available per gram, equivalent at higher concentration., Copper reacts with hydrochloric acid and, liberates hydrogen from the solution of dilute, hydrochloric acid., Hydrogen is below copper in the electrochemical, series.

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Electrochemistry, 5., , Assertion, , :, , Copper liberates hydrogen from a solution of dil., , HCl., Reason, Assertion, , :, :, , Reason, , :, , Assertion, , :, , Reason, , :, , 8., , Assertion, , :, , 9., , Reason, Assertion, Reason, , :, :, :, , Assertion, Reason, Assertion, Reason, Assertion, , :, :, :, :, :, , 6., , 7., , 10., 11., 12., , 13., , 14., , Reason, , :, , Assertion, , :, , Reason, , :, , Assertion, , :, , Hydrogen is below copper in the reactivity series., Zn metal is formed when a Cu plate in dipped in, ZnSO 4 solution., Cu being placed above Zn in electrochemical, series., Electrical conductivity of copper increases with, increase in temperature., The electrical conductivity of metals is due to the, motion of electrons., A small amount of acid or alkali is added before, electrolysis of water., Pure water is weak electrolyte., Copper reacts with HCl and liberates hydrogen., Hydrogen is present above Cu in the reactivity, series., K and Cs are used in photoelectric cells., K and Cs emit electrons on exposure to light., A large dry cell has high e.m.f., The e.m.f. of a dry cell is proportional to its size., The resistivity for a substance is its resistance when, its is one meter long and its area of cross section is, one square meter., The SI uints of resistivity are ohm metre, ( m ) and ohm centimeter ( cm) ., When acidified zinc sulphate solution is, electrolysed between zinc electrodes, it is zinc, that is deposited at the cathode and hydrogen, evolution does not take place., The electrode potential of zinc is more negative, than hydrogen as the overvoltage for the, hydrogen as the evolution on zinc is quite large., If 0Na   0Cl  are molar limiting conductivity of, , 22., , Reason, , :, , Assertion, , :, , Reason, 23., , :, , Reason, , :, , 24., , Assertion, Reason, , :, :, , 25., , Assertion, , :, , Reason, , :, , Assertion, , :, , 26., , The E 0 of zinc is 0.76 V and that of copper, is 0.34 V ., Identification of cathode and anode is done by, the use of a thermometer., Higher is the value of reduction potential, greater, would be its reducing power., An electrochemical cell can be set up only if the, redox reaction is spontaneous., A reaction is spontaneous if free energy change is, negative., Galvanised iron does not rust., Zinc has a more negative electrode potential than, iron., [AIIMS 2005], In an electrochemical cell anode and cathode are, respectively negative and positive electrodes., At anode oxidation takes place and at cathode, reduction takes place., , :, , Assertion, , 525, , Ni / Ni 2 (1.0 M )|| Au 3  (1.0 M )| Au , for this, , cell emf is 1.75 V if E oAu 3  / Au  1.50, o, E Ni,  0.25 V ., 2, / Ni, , 27., , 28., , Reason, , :, , o, o, Emf of the cell  Ecathode, .,  Eanode, , Assertion, , :, , Reason, , :, , Assertion, Reason, , :, :, , Salts like KCl , KNO 3 i.e., inert electrolytes are, used in salt bridge., An inert electrolyte can easily be filled in the Utube., Emf and potential difference are same for cell., Both gives the difference in electrode potential, under any condition., , the sodium and chloride ions respectively, then, the limiting molar conducting for sodium, chloride, is, given, by, the, equation:, 0, 0, 0,  NaCl   Na   Cl  ., Reason, , :, , 15., , Assertion, , :, , 16., , Reason, Assertion, , :, :, , 17., , Reason, Assertion, , :, :, , This is according to Kohlrausch law of, independent migration of ions., One coulomb of electric charge deposits weight, equal to the electrochemical equivalent of the, substance., One Faraday deposits one mole of the substance., Auric chloride ( AuCl3 ) solution cannot be, stored in a vessel made of copper, iron, nickel,, chromium, zinc or tin., Gold is a very precious metal., For a cell reaction Zn(s)  Cu 2  (aq) , 2, , 18., , 19., 20., , 21., , Reason, , :, , Assertion, , :, , Reason, , :, , Assertion, Reason, Assertion, , :, :, :, , Reason, , :, , Assertion, , :, , Zn (aq)  Cu (s) ;, at, the, equilibrium,, voltmeter gives zero reading., At the equilibrium, there is no change in the, concentration of Cu 2  and Zn 2  ions., A negative value of standard reduction potential, means that reduction take place on this electrode, with reference to standard hydrogen electrode., The standard electrode potential of a half cell has, a fixed value., Weston is a standard cell., Its e.m.f. does not change with temperature., Galvanic cells containing hydrogen, methane,, methanol etc. as fuels are called fuel cells., They are designed to convert the energy of, combustion of fuels directly into electrical, energy., Zinc displaces copper from copper sulphate, solution., , and, , Electrolytes and Electrolysis, 1, , b, , 2, , d, , 3, , c, , 4, , c, , 5, , d, , 6, , d, , 7, , b, , 8, , b, , 9, , b, , 10, , a, , 11, , a, , 12, , c, , 13, , d, , 14, , d, , 15, , c, , 16, , d, , 17, , a, , 18, , c, , 19, , c, , 20, , a, , 21, , a, , 22, , b, , 23, , b, , 24, , d, , 25, , b, , 26, , b, , 27, , b, , 28, , a, , 29, , c, , 30, , b, , 31, , d, , 32, , d, , 33, , c, , 34, , b, , 35, , b, , 36, , a, , 37, , d, , 38, , c, , 39, , d, , 40, , a, , 41, , a, , Faraday’s law of electrolysis, 1, , c, , 2, , a, , 3, , b, , 4, , c, , 5, , c, , 6, , c, , 7, , c, , 8, , b, , 9, , c, , 10, , a, , 11, , c, , 12, , a, , 13, , c, , 14, , b, , 15, , b

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526 Electrochemistry, 16, , c, , 17, , a, , 18, , a, , 19, , d, , 20, , c, , 16, , a, , 17, , a, , 18, , c, , 19, , b, , 20, , b, , 21, , d, , 22, , c, , 23, , b, , 24, , d, , 25, , a, , 21, , a, , 22, , b, , 23, , a, , 24, , c, , 25, , a, , 26, , d, , 27, , a, , 28, , d, , 29, , c, , 30, , a, , 26, , a, , 27, , c, , 28, , a, , 29, , d, , 30, , d, , 31, , b, , 32, , b, , 33, , a, , 34, , b, , 35, , b, , 31, , b, , 32, , a, , 33, , d, , 34, , a, , 35, , c, , 36, , b, , 37, , b, , 38, , b, , 39, , a, , 40, , a, , 36, , d, , 37, , a, , 38, , b, , 39, , d, , 40, , d, , 41, , c, , 42, , a, , 43, , a, , 44, , b, , 45, , c, , 41, , b, , 42, , c, , 43, , a, , 44, , b, , 45, , b, , 46, , b, , 47, , d, , 48, , d, , 49, , b, , 50, , a, , 46, , d, , 47, , c, , 48, , b, , 49, , c, , 50, , b, , 51, , c, , 52, , b, , 53, , b, , 54, , a, , 55, , c, , 51, , b, , 52, , a, , 53, , a, , 54, , c, , 55, , a, , 56, , c, , 57, , c, , 58, , d, , 59, , d, , 60, , d, , 56, , a, , 57, , a, , 58, , a, , 59, , c, , 60, , a, , 61, , c, , 62, , c, , 63, , b, , 64, , a, , 65, , b, , 61, , b, , 62, , d, , 63, , a, , 64, , d, , 65, , b, , 66, , b, , 67, , a, , 68, , a, , 69, , b, , 70, , c, , 66, , c, , 67, , b, , 68, , b, , 69, , a, , 70, , b, , 71, , c, , 72, , b, , 73, , a, , 74, , b, , 75, , c, , 71, , b, , 72, , ab, , 73, , c, , 74, , c, , 75, , a, , 76, , b, , 77, , c, , 78, , c, , 79, , b, , 80, , b, , 76, , d, , 77, , b, , 78, , c, , 79, , b, , 80, , a, , 81, , c, , 82, , b, , 83, , a, , 84, , c, , 85, , c, , 81, , a, , 82, , b, , 83, , b, , 84, , c, , 85, , a, , 86, , e, , 87, , b, , 88, , a, , 89, , d, , 90, , c, , 86, , c, , 87, , a, , 88, , c, , 89, , c, , 90, , b, , 91, , c, , 92, , a, , 93, , c, , 94, , b, , 91, , d, , 92, , c, , 93, , d, , 94, , a, , 95, , d, , 96, , a, , 97, , d, , 98, , a, , 99, , b, , 100, , d, , 101, , a, , 102, , c, , 103, , a, , 104, , a, , 105, , d, , a, , 106, , b, , 107, , a, , 108, , b, , 109, , a, , 110, , a, , a, , 112, , b, , 113, , b, , 114, , b, , 115, , b, , Conductor and Conductance, 1, , b, , 2, , b, , 3, , d, , 4, , d, , 5, , 6, , b, , 7, , b, , 8, , a, , 9, , b, , 10, , d, , 111, , 11, , a, , 12, , b, , 13, , b, , 14, , b, , 15, , b, , 116, , b, , 117, , d, , 118, , a, , 119, , d, , 120, , b, , 16, , d, , 17, , b, , 18, , d, , 19, , b, , 20, , c, , 121, , c, , 122, , a, , 123, , a, , 124, , b, , 125, , b, , 21, , b, , 22, , a, , 23, , c, , 24, , d, , 25, , a, , 126, , b, , 127, , b, , 128, , a, , 129, , a, , 26, , b, , 27, , d, , 4, , a, , Corrosion, Cell constant and Electrochemical cells, , 1, , b, , 2, , d, , 3, , d, , 1, , d, , 2, , d, , 3, , d, , 4, , b, , 5, , b, , 6, , a, , 7, , c, , 8, , c, , 9, , b, , 10, , b, , 11, , c, , 12, , c, , 13, , a, , 14, , a, , 15, , d, , 1, , c, , 2, , a, , 3, , c, , 4, , b, , 5, , c, , a, , 7, , a, , 8, , b, , 9, , acd, , 10, , a, , c, , 12, , d, , 13, , c, , 14, , c, , Critical Thinking Questions, , 16, , c, , 17, , c, , 18, , a, , 19, , b, , 20, , b, , 6, , 21, , b, , 22, , b, , 23, , a, , 24, , b, , 25, , c, , 11, , 26, , a, , 27, , c, , 28, , a, , 29, , b, , 30, , c, , 31, , a, , 32, , b, , 33, , c, , 34, , b, , 35, , d, , 36, , b, , 37, , c, , 38, , d, , 39, , b, , 40, , d, , 1, , a, , 2, , b, , 3, , a, , 4, , d, , 5, , d, , 41, , a, , 42, , d, , 43, , c, , 44, , a, , 45, , d, , 6, , d, , 7, , e, , 8, , a, , 9, , e, , 10, , a, , 46, , a, , 47, , d, , 48, , b, , 49, , c, , 50, , c, , 11, , d, , 12, , b, , 13, , a, , 14, , a, , 15, , c, , 51, , b, , 52, , d, , 53, , c, , 54, , a, , 55, , c, , 16, , b, , 17, , a, , 18, , e, , 19, , a, , 20, , a, , c, , 21, , a, , 22, , d, , 23, , b, , 24, , a, , 25, , a, , 26, , a, , 27, , c, , 28, , d, , 56, , d, , 61, , a, , 57, , b, , 58, , a, , 59, , a, , 60, , Electrode potential, ECell, Nernst equation and ECS, 1, , b, , 2, , a, , 3, , a, , 4, , b, , 5, , d, , 6, , c, , 7, , c, , 8, , a, , 9, , a, , 10, , b, , 11, , a, , 12, , c, , 13, , a, , 14, , d, , 15, , c, , Assertion & Reason