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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , ALCOHOLS, Ø, , SYNOPSIS, Ø, , Ø, , Ø, , Alcohols are the hydroxyl derivatives of, hydrocarbons i.e., obtained by the replacement, -H, → R-OH, of one or more H atoms R-H , +OH, The compound in which a hydroxyl group is, attached to a saturated carbon atom are called, alcohols., Eg:- 1)CH 3OH 2)C2 H 5OH, The compounds in which hydroxyl group is, attached to an unsaturated carbon atom of a, double bond are called ‘enols’.Eg;- H 2C=CH-OH, , Tertiary Alcohols (30): In these alcohols the –, , OH group is attached with tertiary carbon atom, They posses a general formula R3C-OH, CH 3, C2 H5 - C - OH, , Eg:, , Tert. amyl alcohol, , CH 3, , Allyl alcohols: In these alcohols the –OH group, is attached a sp3 hybridized carbon atom next to, the carbon – carbon double bond i.e. to an allylic, carbon., , Classification: Alcohols are classified, , Ø, Ø, , according to the number of hydroxyl groups, present in their molecules., Monohydric alcohols contain one –OH group,, dihydric two and trihydric three, respectively., Monohydric alcohols are further classified, according to the hybridization of carbon atom, to which the –OH group is attached., , Ø, , 44, , Allyl alcohol, , But-3-en 2-ol, Benzyl Alcohols: In these alcohols, the –OH, group is attached to sp3 hybridised carbon next, to an aromatic ring., , Compounds containing Csp -OH bond:, , Eg:-, , In these alcohols the –OH group is attached to a, sp3 hybridised carbon atom of an alkyl group. Ø, These are further subdivided as follows, , Hence, allylic and benzylic alcohols may be, primary, secondary or tertiary., , 3, , Ø, , Eg: H 2C = CH-CH 2 -OH, , Primary Alcohols (10): In these alcohols the, , Compounds containing Csp2-OH bond:, , –OH group is attached with primary carbon atom, In these alcohols, the –OH group is attached to, a carbon atom of the double bond, i.e., vinylic, They posses a general formula RCH2OH. R may, carbon or to an aryl carbon., be H in the first member and alkyl group in the, Eg: H2C=CH-OH – Vinyl alcohol, rest of the members., Eg: HCH2OH, Methyl alcohol, CH3CH2OH, Ethyl alcohol, CH3CH2CH2OH, n – propyl alcohol, 0, Secondary Alcohols (2 ):In these alcohols the, –OH group is attached with secondary carbon, Note:, atom.They posses a general formula R2CHOH., Ø When two or more hydroxyl groups are attached, CH, CH, CH, CH, to the same carbon atom, the compound is, CH 3 - CH - CH 3, 3, 2, 3, usually unstable. This unstable compound, Eg:, OH, OH, looses a water molecule and gets converted to a, stable compound., Isopropyl alcohol Secondary butyl alcohol, NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , IUPAC system: According to this system, , Ø, , But inspite of having two hydroxyl groups to the, same carbon atom, chloral hydrate CCl3CH(OH)2, is a stable compound. The unusual stability of chloral, hydrate has been attributed to the –I effect of Ø, chlorine and to the formation of intramolecular, Eg:, hydrogen bonds., , alcohols are called alkanols., Methanol, Eg:CH3OH, CH3CH2OH Ethanol, CH3 - CH 2 - CH 2 - CH 2 - OH Butan – 1 - ol, Isomerism: Alcohols may exhibit chain,, positional and functional isomerism., Functional isomers of alcohols are ethers., CH3 –CH 2 –CH 2 –CH 2, OH, , and, , CH 3 –CH–CH 2, |, |, CH 3 OH, , are chain isomers, CH3 –CH 2 –CH 2 –CH 2, OH, , Ø, , Nomenclature: There are three systems of, Ø, naming the alcohols., , Ø, , Common system: In this system alcohols are, named as alkyl alcohols i.e., the word alcohol, is added to the name of alkyl group., In higher members, it is always indicated Ø, whether the –OH group is attached to primary,, secondary or tertiary carbon atom by prefixing Ø, ‘n’ for primary, sec for secondary and tert for, tertiary., Eg; CH3OH, Methyl alcohol, CH3CH2OH, Ethyl alcohol, CH3CH2CH2OH n-propyl alcohol, OH, |, Sec.butyl alochol, CH 3 − CH 2 − CH − CH 3, , Ø, Ø, , and, , CH 3 –CH–CH 2 –CH 3, OH, , are position isomers, CH3–CH2–OH and CH3–O–CH3 are functional, isomers., Unsaturated alcohols and carbonyl compounds, are tautomers., CH3 –C=CH 2 and CH3 –C–CH3, , OH, , O, , are tautomers., , Alcohols containing chiral centres can exhibit, optical isomerism., The simplest monohydric alcohol that can, exhibit enantiomerism is butan–2–ol., H, |, CH 3 − C − OH, |, C2 H 5, , W.E-1:Identify the most stable conformer of glycol., , Sol. Gauche form of glycol is most stable. This is, due to intramolecular hydrogen bonding., Carbinol system: The simplest monohydric, alcohol CH3OH is called carbinol., All other members are considered its alkyl, derivatives., The alkyl groups attached to the carbon atom, carrying –OH group are named in alphabetical, order., CH3CH2OH, Eg:CH3OH, Carbinol, Methyl carbinol, Dimethyl carbinol, , W.E-2:Glycerol does not contain ....alcoholic group, Sol. Tertiary, , NARAYANAGROUP, , 45
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , Hydrolysis of Ester: Esters on hydrolysis, , Absolute alcohol is 99.6 to 100% pure ethyl, alcohol., , gives acid and alcohol., +, , H, → R-COOH + R1 - OH, RCOOR1 + H 2 O , or HO-, , Ø, , Alcohols being more volatile than acid an hence Ø, it can easily be separated by distillation., Ester hydrolysis involves the cleavage of C–O, bond of, , Ø, , By Fermentation:Decomposition of large, , Ø, Ø, , compounds into simple compounds by enzymes, derived by mirco organisms like yeast is called, Ø, fermentation., Enzymes are biocatalysts which are non living, Ø, nitrogenous compounds., They catalyse reactions taking place in living, organism and act as specific catalysts. Yeast is, a single cell microorganism., , From Molasses: Molasses is the mother liquor, Ø, Ø, Ø, Ø, , Ø, , Ø, , Ø, Ø, Ø, Ø, , left after seperation of sugar from sugar cane, juice., It is black and viscous and still contains 20-40%, sucrose., It is diluted with water so that the percentage of, sugar in it is 10%., Then H2SO4 is added to maintain the pH at 4., Ammonium sulphate or phosphate is added, which serves as food for yeast. Then yeast is, added and the mixture is taken and retained in, large wooden tank for 2–3 days at 30°C – 40°C., An enzyme, invertase produced by yeast, converts sucrose into glucose and fructose., INVERTASE, C12H22O11 + H2O , → C6H12O6 +, C6H12O6, Another enzyme, zymase converts glucose and, fructose into ethyl alcohol., ZYMASE, C6H12O6 , → 2CH3CH2OH + 2CO2, The fermented solution contains 6–10% ethyl, alcohol and is called wash or wort., This dilute solution on fractional distillation, gives rectified spirit containing 93-95% alcohol., Generally 95-96% alcohol is called as Rectified, spirit (or) industrial alcohol., It is converted to absolute alcohol by drying on, treating with quick lime and then over calcium., , NARAYANAGROUP, , From Starch: A suspension of starch is made, by heating with water at 50°C., Germinated barley called malt is added. Malt, contains diastase, which converts starch to, maltose., DIASTASE, 2(C6H10O5)n + nH2O , → nC12H22O11, The mixture is cooled to 30°C and yeast is, added. An enzyme, maltase produced by yeast, converts maltose into glucose., MALTASE, C12H22O11 + H2O , → 2C6H12O6, Zymase converts glucose to ethyl alcohol., ZYMASE, C6H12O6 , → 2CH3CH2OH + 2CO2, Methyl alcohol is prepared from water gas, enriched with H 2 in presence of oxides of, chromium and zinc. It is also prepared by the, partial oxidation of methane., ZnO, Cr2 O3 , 200atm,600K, CO + 2H2 , → CH3OH, , 2CH4 + O2, Ø, Ø, Ø, , 0, , Cu, 250 C,100atm, , → 2CH3OH, , Mineralised methylated spirit : 90%, rectified spirit +9% methyl alcohol +1%, petroleum oil and a purple dye., Industrial methylated spirit : 95% rectified, spirit +5% methanol., Denatured alcohol is unfit to consume as it, contains CuSO4, pyidine or methanol. Industrial, alcohol is also made unfit for drinking by adding, methyl alcohol., , W.E-3:How acetylene is converted to ethyl alcohol?, Sol. Acetylene on hydration gives acetaldehyde,, which on reduction gives ethanol., HgSO4, LiAlH 4, → CH3 - CHO , → C2 H5OH, HC ≡ CH + H 2 O , H 2SO4, , W.E-4:How benzyl alcohol is obtained from benzyl, chloride ?, Sol. Benzyl chloride on base hydrolysis gives benzyl, alcohol., , 47
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , Physical properties of Alcohols:, Ø, , Ø, , Ø, , Ø, , Ø, , Ø, , Ø, , Ø, , Ø, , Ø, , 48, , Alcohols have higher boiling points than, hydrocarbons, ethers, aldehydes and ketones of, comparable molecular masses. Alcohols have, greater intermolecular attractions arising due to, intermolecular hydrogen bonds. The tendency, of formation of hydroegn bonds is, 10 > 20 > 30 alcohols, The boiling points of alcohols increase with an, increase in molecular mass arising due to vander, Waals forces., Alcohols and ethers are functional isomers but, the boiling point of alcohol is greater than, corresponding ether due to formation of, intermolecular hydrogen bonds., Eg. Order of boiling points : Methanol < Ethanol, < Propanol < Butanol., In case of alcohols with same alkyl group,, boiling point decreases with increasing, branching., Eg. n–Butyl alcohol > Iso butyl alcohol > tert., Butyl alcohol., Alcohols are soluble in water due to hydrogen, bonding between molecules of alcohol and, water., Solubility in water decreases with an increase, in the size of non polar hydrophobic alkyl group,, which resists dissolution., Eg. Order of solubility : CH3CH2OH >, CH3CH2CH2CH2OH > CH3(CH2)4CH2OH, Among isomeric alcohols, solubility decreases, with increase in surface area., Eg. tert. Butyl alcohol > Isobutyl alcohol >, n–Butyl alcohol., The boiling point of methanol is 670C., Methanol is highly poisonous in nature., Ingestion of even small quantities can cause, blindness and large quantities causes even death., Ethanol is a sweet smelling colourless liquid. It, is soluble in water as well as organic solvents., Its boiling point is 78.1°C, Ethyl alcohol has burning taste and burns with, blue flame. A mixture of 95.6% ethyl alcohol, and 4.4% water forms constant boiling mixture, called as azeotropic mixture. Since it forms an, , Ø, , addition compound with CaCl2, it cannot be used, for drying ethyl alcohol., Ethyl alcohol is obtained from starchy grains and, so is called as grain alcohol and as it is a constituent, of wines, it is called as spirit of wine, , Chemical properties: The hydroxyl group, , Ø, , Ø, , Ø, , Ø, Ø, , Ø, , Ø, , present in alcohols is a very reactive group and, the characteristic reactions of alcohols are the, reactions of –OH group, The reactions of hydroxyl group consists of, either cleavage of C – O bond of the cleavage, of O – H bond., ‘C – O bond is weaker in the case of tertiary, alcohols due to +I effect of alkyl groups while, O – H bond is weaker in primary alcohols as, electron density increases between O – H bond, and hydrogen tends to separate as a proton., Hence in O – H cleavage, the order of, reactivity is Primary > Secondary > Tertiary, and in C – O cleavage the order of reactivity, is Tertiary > Secondary > Primary., During O – H cleavage proton is given out, showing that alcohols are acidic in nature., However, alcohols are weaker acids than water., This is because the alkyl groups in alcohols have, +I effect., Hence the following order is followed in the, acidic nature of alcohols., CH 3OH > Primary alcohol > Secondary, alcohol > Tertiary alcohol, In general the reactions of alcohols may be, divided into following three categories., (a) Reactions involving the cleavage of O – H, bond [C – O – H]with substitution or removal, of hydrogen as proton(i.e., alcohols act as, nucleophiles), (b) Reactions involving the cleavage of carbon, – oxygen bond [C – OH] with substituion or, removal of –OH group (i.e., aclohols acts as, electrophiles)., (c) Reactions involving both the cleavage of, alkyl and the hydroxyl groups of the alcohol, molecules., NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , Reaction with Metals: Alcohols react with W.E-6:Assertion (A): Dehydration of alcohols can be, metal to form metal alkoxide and evolve H2., This reaction is acid – base reaction., , Ø, , carried out with Conc H 2SO 4 but not with, conc.HCl., Reason (R) : H2SO4 is dibasic while HCl is, 1, R - OH + M → R - OM + H 2 (M = Na, K etc), monobasic., 2, 1) Both A and R are true and R is the correct, 1, Eg: C 2 H 5OH + K → C 2 H 5OK + H 2, explanation to A, 2, 2) Both A and R are true and R is not the correct, Metal hydrides react with alcohol and evolve, explanation to A, H2 gas., 3) A is true but R is false, R-OH + MH → R - OM + H 2 (M = Na, K etc), 4) A is false but R is true, Dehydration of Alcohols: Alcohols when Sol. ‘2’, heated in presence of conc., W.E-7:Hydroboration-Oxidation of CH 3CH = CH 2, H2SO4 (170 – 1800C) or H3PO4, Al2O3 or P2O5, produces., undergoes dehydration to form alkene., 1. CH 3CH 2CH 2OH, 2. CH 3CH (OH ) CH 3, 0, , H SO ,160 C, Eg: CH3 - CH 2 - OH , → H 2 C = CH 2 + H 2 O, 2, , Ø, Ø, Ø, , 4, , 3. CH 3CH (OH ) CH 2OH 4. CH 3COCH 3, Order of ease of dehydration of alcohols:, Sol. ‘1’, 30 > 20 > 10, Stability order of alkene: More substituted, W.E-8:The compound which gives the most stable, alkene is more stable (due to hyper conjugation), carbonium ion on dehydration., Ease of dehydration:, CH 3, CH 3, , 1., , CH, CH 3, , CH 2OH, , 2., , CH 3, , C, , OH, , CH 3, , Ø, , Alcohols when heated with conc. H2SO4 at 383, 3., CH 3CH 2CH 2CH 2OH, K (1100C) give dialkyl sulphate and at 413 K, CH 3 CH CH 2CH 3, (1400C) give ether. At 443 – 453 K (170 –, 0, 4., 180 C) they give alkene., OH, Ø Alcohols when heated with alumina (Al2O3) at, Sol. ‘2’., 513 – 523 K (240 –2500C) give ether and at 633, Note:Primary alcohols undergo dehydration by E2, K (3800C) give alkene., mechanism(tertiary or neo carbon is not present, Ø No rearrangement takes place in E2 mechanism., at β poistion) while secondary and tertiary, W.E-5: Predict the major product of dehydration, alcohol undergo dehydration by E1 mechanism., of each of:, Ø Regardless the type of alcohol, however, strong, acid is always needed to protonate the O atom, (A) (CH3)2C(OH)CH2CH3, to form a good leaving group., (B) (CH3)2CHCH(OH)CH3, Ø With 10 alcohols, however, loss of the leaving, (C) (CH3)C(OH)CH(CH3)2, group and removal of a proton occur at the same, CH3, H 3C, CH3, time, so that no highly unstable primary, (C ), H 3 C C CHCH 3, (A, ), and, (B, ), C, C, carbocation is generated., Sol., H 3C, , NARAYANAGROUP, , CH3, 49
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , Rearrangement in the Alicyclic ring: Ø Primary alcohols are oxidized to either aldehyde or, In case of cyclic alcohols whenever a, carbocation is formed outside the next carbon, atom of a ring, ring expansion may takes place., , Examples of ring expansion:, , to carboxylic acids by replacing either one or two, C – H bonds by C – O bonds., [O], [O], R - CH 2 -OH , → R-CHO , → R-COOH, , Ø, , Ø, , Secondary alcohols are oxidized to ketones by, replacing one C – H bond by a C – O bond., [O], → R2- C = O, R 2 - CH - OH , Tertiary alcohols have no H atom on the carbon, with OH group, so they are not oxidized., , Reaction with HX: The reaction of alcohols, , with HX (X = Cl, Br) is a general method to Ø, prepare primary, secondary and tertiary alkyl, halide., HBr, , → CH 3CH 2 Br + H 2 O, CH 3 - CH 2 - OH , , Ø, Ø, Ø, Ø, , Oxidation with Ceric ammonium nitrate (CAN), is a very selective reagent for the mild oxidation, of primary alcohol. The reagent also oxidise, aromatic methyl group into – CHO., CAN, → CH 3 - CHO, CH 3 - CH 2 - OH , , More substituted alcohols usually react more, rapidly with HX., Order of reactivity of alcohols with HX is, Tertiary > Secondary > Primary., Ø Manganese dioxide (MnO2) is selective and, Primary alcohols form R – X by SN2 reaction, mild oxidant. It is specific for allylic and, while secondary and tertiary alcohols form R–X, benzylic alcohols., by SN1 reaction., MnO2, → H 2 C= CH - CHO, Because carbocation is formed in SN1 reaction H 2 C = CH - CH 2 - OH , of secondary and tertiary alcohols with H X ,, Oppenauer Oxidation: The reaction involves, carbocation rearrangement is also possible., the oxidation of secondary alcohols with a, ketone and a base to the corresponding ketone, Reaction with PX5: The treatment of PX5 with, of the alcohol., primary and secondary alcohols forms an alkyl, Al(OCMe), halide., →, R 2 - CH - OH , CH -CO-CH, 3, , 3, , R- OH + PCl3 → R - Cl + H 3 PO3, R- OH + PCl5 → R - Cl + POCl3 + HCl, , Oxidation of Alcohols: Alcohols are, Ø, 50, , 3, , R - CO - R + CH 3 - CH(OH) - CH 3, , Haloform reaction: Compounds having methyl, keto group react rapidly with halogen in presence, of a base to form haloform., , oxidized to carbonyl compounds depending on R - CO - CH 3 + 3X 2 + 4NaOH → CHX 3 + RCOONa, the type of alcohol and reagent., Ø Ethyl alcohol gives positive haloform test., Oxidation occur by replacing C – H bond on, NaOH + Cl2, C2 H 5OH + NaOCl , → CHCl3 + HCOONa, the carbon bearing OH group by C – O bond., NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , METHODS OF DISTINGUISHING BETWEEN PRIMARY, SECONDARY, AND TERTIARY ALCOHOLS:, , 52, , NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , 13. Primary,secondary and tertiary alcohols are, distinguished by, 1) oxidation method, 2) Lucas test, NOMENCLATURE, 3) Victor Meyer’s method 4)all the above, 1. 2,4-dimethyl -3-pentanol is a, 14. The reaction between an alcohol and, 1) primary alcohol, 2) secondary alcohol, carboxylic acid leads to the formation of, 3) tertiary alcohol, 4) dihydric alcohol, 1) Aldehyde 2) Ester 3) Ketone 4) Paraffins, 2. Which of the following is a tertiary alcohol 15. Alcoholic is beverages contain, 1) Glycerol, 2) Ethyl alcohol, 1) (CH 3 )2 CHCH 2OH 2) CH 3CH 2CH 2CH 2OH, 3) Methyl alcohol, 4) Isopropyl alcohol, 3) CH 3CH 2CH 2OH, 4) (CH 3 )3 COH, 16. Ethyl alcohol on oxidation with acidified, K2Cr2O7 gives, PREPARATION, 2) HCOOH, 1) CH3COCH3, 3. The enzyme which converts glucose to, COOH, 4) HCHO, 3), CH, ethylalcohol is, 3, Pd − BaSO4 / Quinoline, 1) zymase 2) invertase 3) maltase 4) diastase, 17. H − C ≡ CH + H 2 , →A, 4. Whichof the following is Lucas reagent, HCl, KOHaq, B , →, →C, 1) ammonical silver nitrate 2) Br2 / CCl4, Here the ‘C’ is, 3) dry ZnCl2 / con. HCl, 4) alk.KMnO4, 1) Propane 2) Ethanol 3) Ethyne 4) Ethylene, 5. Ethyl alcohol is the hydrolysis product of, 18. A compound (X) of molecular formula C3H8O, 1) C2H5Cl 2) CH3CHO 3) C2H4 4) C2H5 MgI, can be oxidized to a compound of molecular, formula C3H6O2 (Y), (X) is most likely an, PROPERTIES, 1) Aldehyde, 2) Alcohol, 6. 95% ethyl alcohol can be converted to, 3) Ether, 4) Both 2 and 3, 100% ethyl alcohol by the following, 19., Which, of, the, following, gives Iodo form test, 1) Magnesium chloride 2) Calcium oxide, 1) CH3—CH2—CH2—OH 2) CH3—CH2—OH, 3) Magnesium phosphate 4) Magnesium sulphate, 3), CH3—CH(OH)—CH3 4) Both 2 and 3, 7. In wash or wort possess ---- percentage of, 20. There are three alcohols x,y,z which have 2,1, ethyl alcohol, and 0 alpha hydrogen atom(s) respectively., 1) 95%, 2) 100% 3) 66.9% 4) 6 - 10%, 8. CaCl2 + C2H5OH —> CaCl2. xC2H5OH. ‘x’ is, Which does not give Lucas Test immediately, 1) 3, 2) 6, 3) 2, 4) 1, 1) x 2) y 3) z 4) all the three do not give test, 9. Ethanol and Methanol are miscible in water, LEVEL -I (C.W) - KEY, due to, 1) Dissociation of water 2) Their acidic character, 1) 2 2) 4 3) 1 4) 2 5) 1 6) 2 7) 4, 3) Allyl groups, 4) Hydrogen bonding, 8) 1 9) 4 10) 4 11) 4 12) 4 13) 4 14) 2, 10. To bring about dehydration of alcohols we, 15) 2 16) 3 17) 2 18) 2 19) 4 20) 1, can use, , LEVEL-I (C.W), , 1) Conc. H 2 SO4 2) Al2O3 3) ZnO 4) both 1,2, 11. The reaction 2 ROH + 2 Na → 2 RONa + H 2, suggests that alcohols are, 1) basic, 2) amphoteric, 3) neutral, 4) acidic, 12. Which of the following reaction conditions, are used for the conversion of ethanol to, ethylene., , LEVEL -I (C.W) - HINTS, 1., 2., 3., 4., , 1) conc. H 2 SO4 / 700 C 2) dil. H 2 SO4 /1400 C, 3) dil. H 2 SO4 /1000 C, NARAYANAGROUP, , 4) conc. H 2 SO4 /1700 C, , 5., 6., , (CH 3 )3 C − OH, Zymase, Glu cos e , → ethyl alcohol, Lucas reagent is a mixture of, Conc.HCl + anh ZnCl2, Alkyl halides on hydrolysis gives alcohols, CaO, , 53
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , 7., 6 − 10% C2 H 5OH, X=3, Ethanol and methanol form hydrogen bond with, water, 10. Conc.H 2 SO4 and Al2O3 are dehydrating agents, 11. acidic, 8., 12. 1700 C , con H 2 SO4, 7., 8., 9., , 13. any one, H, 14. ROH + RCOOH , → RCOOR + H 2O, +, , 15. C2 H 5OH, 16. C2 H 5OH is 10 - alcohol, 17. A = C2 H 4 B = C2 H 5Cl C = C2H5OH, 18. X = CH 3 − CH 2 − CH 2 − OH (C3 H 8O ), Y = CH 3 − CH 2 − COOH (C3 H 6O2 ), , 19. CH 3CO group is present, 20. X= RCH 2OH ;, , Y= R2CHOH, , LEVEL-I (H.W), 1., , 2., , 3., , 4., , 5., , Absolute alcohol cannot be obtained by simple, fractional distillation because, 1) pure C2 H 5OH is unstable, , 2) C2 H 5OH forms chemical bonding with water, 3) Oxidation, 4) it forms azeotropic mixture with water., The number of 10 , 20 and 30 alcoholic groups, in Mannitoal or Sorbitol are respectively, 1) 2, 4 and 0, 2) 1, 4 and 0, 3) 2, 2 and 0, 4) 2, 1 and 1, 9. An isomer of ethanol is, 1) Methanol, 2) Dimethyl ether, 3) Diethyl ether, 4) Ethyl glycol, 10. Which one of the following is a secondary alcohol ?, 1) 2 - Methyl - 1 - propanol, 2) 2 - Methyl - 1 - propanol, 3) 2 - Butanol, 4) 1 - Butanol, 11. If the boiling point of ethanol (molecular, weitht = 46) is 780 C , the boiling point of diethyl ether (molecular weight = 74) is, 1) 1000 C 2) 780 C 3) 860 C 4) 340 C, , Which of the following is a tertiary alcohol 12. The percentage of C2 H 5OH in wash is, 1) Ethyl alcohol, 2) Isopropyl alcohol, (approximatly), 3) Neopentyl alcohol 4) 2-methyl 2-propanol, 1) 95%, 2) 10%, 3) 50%, 4) 75%, Glycerol does not contain ........ alcoholic 13. Which of the following alkenes when passed, group, through conc. H 2 SO4 followed by hydrolysis, 1) 10, 2) 20, 3) 30, 4) 10 and 20, with boiling water would give tert - butyl, PREPARATION, alcohol ?, Which of the following enzyme converts, 1) Ethylene, 2) Isobutylene, maltose to glucose, 3) Propylene, 4) 1 - Butene, 1) Invertase 2) Zymase 3) Maltase 4) Diastase 14. Which one of the following gases is liberated, Absolute alcohol is prepared from rectified, when ethyl alcohol is heated with methyl, spirit by, magnesium iodide ?, 1) Steam distillation 2) Fractional distillation, 1) Methane, 2) Ethane, 3) distillation with CaO &Ca, 3) Carbondioxide, 4) Propane, 4) Simple distillation, 15. Identify A and B in the following reaction, 673 k ,300 atm ,/ Cr2 O3 − zno, A, B, +, CO, H, 2, Reaction,, 2( g ) →, → C2 H 5OH ←, C2 H 5Cl, C2 H 5 − Cl , may be used for manufacture of :, 1) A = aqueous KOH; B = moist Ag2O, 1) HCHO, 2) CH3COOH, 2) A = alcoholic KOH ; B = aqueous NaOH, 3) HCOOH, 4) CH3OH, 3) A = aqueous NaOH ; B = AgNO2, , PROPERTIES, , 6., , 54, , 4) A = AgNO2 ; B = KNO2, When wine is exposed to air it become sour, 16. 23g of sodium will react with methanol to give, due to, 1) One mole of oxygen 2) 1/2 Mole of hydrogen, 1) Oxidation of C2H5OH into CH3COOH, 3) One mole of hydrogen 4) 1/4 Mole of oxygen, 2) Bacteria 3) Virus 4) Formic acid formation, NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, 17. The correct order of decreasing basicity of, the following species is :, H 2O, OH − , CH 3OH , CH 3O −, , 1) CH 3OH < H 2O < OH − < CH 3O −, 2) OH − > CH 3O − > CH 3OH > H 2O, 3) H2O < CH3OH < CH3O− < OH −, , 14. Methane, 15. aq. KOH and AgOH, 16. As per stoichiometry, 17., 18., 19., 20., , 4) OH − > CH 3O − > CH 3OH > H 2O, 18. Which of the following alcohols is expected to, have the lowest pK a value ?, 1) Ethanol, 2) 2-Fluoro ethanol, 1., 3) 2,2,2-Trifluoroethanol 4) 2-Chloroethanol, 19. Action of bleaching powder on ethyl alcohol, gives, 1) Chloroform, 2) Dichloromethane, 3) Trichloroethane, 4) Ethylenechloride, 20. Which is formed when ethanol reacts with acetic acid, 2) C2 H 5OC2 H 5, 1) CH 3COOC2 H 5, 2., 3) CH 3OCH 3, 4) CH 3CH 2CHO, , LEVEL -I (H.W) - KEY, 1) 4 2) 3 3) 3 4) 3 5) 4 6) 1 7) 4, 8) 1 9) 2 10) 3 11) 4 12) 2 13) 2 14) 1, 15) 1 16) 2 17) 2 18) 3 19) 1 20) 1, , (CH 3 )3 C − OH, , 2., , 3., 4., 5., 6., 7., 8., 9., 10., 11., 12., 13., , 3., , 4., , NOMENCLATURE, Which one of the following pairs of, compounds are functional isomers of each, other, 1) CH 3CH 2CH 2OH , CH 3CHOHCH 3, 2) CH 3CH 2CH 2OH , (CH 3 )2 CHCH 2OH, 3) CH 3CH 2CH 2OH , CH 3CH 2CH 2Cl, 4) CH 3CH 2CH 2OH , CH 3OCH 2CH 3, Primary alcoholic group is, , Ethyl alcohol containing 9.5% methyl alcohol, and 0.5% pyridine is called, 1) Spirit, 2) Denaturated spirit, 3) Rectified spirit, 4) Absolute alcohol, Breaking of big organic molecules in the, presence of enzymes is called, 1) Cracking, 2) Pyrolysis, 3) Fermentation, 4) Oxidation, , PROPERTIES, 5., , Maltase, Maltose , → glu cos e, 6., CaO + Ca, Rectified spirit , → absolute alcohol., Industrial preparation, Oxidation, 7., azeotropic mixture., On the basis of structure, Alcohols and ethers containing the same number of, carbon atoms are functional isomers, 8., -OH group is on the secondary carbon, b.p of alcohol is greaterthan ether, ‘Wash’ contains about 10% ethyl alcohol, Isobutylene, , NARAYANAGROUP, , LEVEL-II (C.W), , PREPARATION, , CH 2 OH, |, H-C-OH, is glycerol, |, CH 2 OH, , CH 3COOC2 H 5, , 1) -CH2OH 2) − C − OH 3) >CHOH 4) >C=O, , LEVEL -I (H.W) - HINTS, 1., , OH − > CH 3O − > CH 3OH > H 2O, More acidic, Chloroform, , Which alcohol is most reactive towards, HCl in the presence of anhydrous ZnCl2 ?, 1) primary 2) secondary 3) tertiary 4) all of these, Isopropyl alcohol on oxidation forms, 1) Ethylene, 2) Acetone, 3) Ether, 4) Acetaldehyde, When tertiary butyl alcohol is passed over, reduced copper, the reaction taking place is, 1) oxidation, 2) reduction, 3) dehydration, 4) substitution, When ethylalcohol reacts with Br2 in presence, of red phosphorus the compound formed is, 1) C2H6, , 2) PBr3, , 3) CH3Br 4) C2H5Br, 55
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, 5., , Order of reactivity of alcohols towards Lucas 4., reagent is 30 > 20 > 10, , 6., 7., , 5., (P ), , 8., , 4 n, C2 H 5OH + Br2 , → C2 H 5 Br + HBr, , 9., , Addition reactions of C2 H 5OH, , An organic compound ‘A’ containing C,H and, O has a pleasant odour with boiling point 780C., On boiling ‘A’ with conc H2SO4,a colourless, gas is released. The organic liquid ‘A’ is:, 1) C2H5 Cl, 2) C2H5 COOCH3, 3) C2H5OH, 4) C2H6, When equal weights of methyl alcohol and, ethyl alcohol react with excess of sodium, metal, the volume of H 2 liberated is more in, the case of, , 10. 20 (or ) 30 alcohols on oxidation give ketone, , 1) C2 H 5OH, , 11. A = CH3OH, B = CH3ONa, C = CH3Cl, , 3) Equal in both, 4) H 2 is not liberated, Which one of the following gases is liberated, when ethyl alcohol is heated with methyl, magnesium iodide ?, 1) Methane, 2) Ethane, 3) Carbondioxide, 4) Propane, Which one of the following alcohols is, expected to have the lowest P Ka value ?, , 6., 12. A = CH 3COOH , B = C2 H 5OH, 13. Alcohols are converted into haloalkanes with, Phophorous trihalides, 14. Methyl magnesim bromide and acetone, 15. A = C2 H 5Cl , B = C2 H 5ONO, 7., 16. The reactivity of alcohols with active metals is, 30 < 20 < 10, 17. The correct decreasing order of dehydration of, the given alcohols with acids like conc. H 2 SO4 8., is 30 > 20 > 10, 18. The reaction occur with rearrangement as, 20 carbocation is more stable than 10 carbo, cation., 19. Correct order or reactivity is, , CH 3OH > CH 3CH 2OH > (CH 3 )2 CHOH, , 2) CH 3OH, , 1) Ethanol, 2) 2-Fluoro ethanol, 3) 2,2,2-Trifluoroethanol 4) 2-Chloroethanol., R − OH + HX → R − X + H 2O ., In this reaction, the reactivity of alcohols is, 1) Tertiary > Secondary > Primary, 2) Tertiary < Secondary < Primary, 3) Tertiary > Primary > Secondary, 4) Secondary > Primary > Tertiary, , 9., , (i ) CH3MgBr, mild oxidation, → X , →Y, (CH3 )2 CHOH , H2O, 0, 20. 3 carbonium ion more stable, Here ‘Y’ is, 1) Iso butyl alcohol 2) Iso butylene, 21. Acetaldehyde on reaction with Grignard reagent, 3) sec.Butyl alcohol 4) tert.Butyl alcohol, to give a secondary alcohol, 10. Haloform reaction is not given by, , LEVEL-II (H.W), 1., , 2., , 3., , 1) CH 3COCH 3, , 2) CH 3COC2 H 5, , 3) C6 H 5COC2 H 5, 4) CH 3CHOHCH 3, 2-Methylpentanol-1 is a, 11. What is the final product obtained when chlo2) 20 alcohol, 1) 10 alcohol, rine reacts with ethyl alcohol in KOH?, 4) enol, 3) 30 alcohol, 1) CHCl3 2) CCl3CHO 3) CH 3Cl 4) none, Primary alcohol cannot be prepared by the, reduction of, KMnO4 / H ⊕, Y, →, X , 12. C2 H 5OH →, H 2 SO4, 1) aldehyde 2) acid 3) ketone 4) ester, The two enzymes present in yeast that are, CH 3COOC2 H 5 , X and Y respectively are, responsible for the formation of ethylalcohol, 1) CH 3OH ; C2 H 5OH, 2) CH 3CHO; CH 3OH, from molasses in the fermentation process are, 3) CH 2 = CH 2 ; CH 3COOH 4) CH 3COOH ; C2 H 5OH, 1) Invertase, zymase 2) Invertase, diastase, 3) Zymase, diastase 4) Invertase, maltase, NARAYANAGROUP, , 57
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , 13. R − OH + HX → R − X + H 2O . In this reaction, the reactivity of alcohols is, 1) Tertiary > Secondary > Primary, 2) Tertiary < Secondary < Primary, 3) Tertiary > Primary > Secondary, 4) Secondary > Primary > Tertiary, 14. Match the following lists, List - I, List - II, A) Ethlene, 1) Natalite, B) Acetylene, 2) Preservative, C) Ethanol, 3) Hawker’s lamp, D) Diethyl ether, 4) Drug, 5) Polyethylene, Correct match is :, A B C D, A B C D, 1) 3 2 1 5 2) 5 1 2 3, 3) 5 3 2 1 4) 5 1 4 2, 15. 3 moles of ethanol react with one mole of, phosphorous tribromide to form 3 moles of, bromo ethane and one mole of X. Which of, the following is “X”, , LEVEL -II (H.W) - KEY, 1) 1 2) 3 3) 1 4) 3 5) 2 6) 1 7) 3, 8) 1 9) 4 10) 3 11) 1 12) 4 13) 1 14) 3, 15) 4 16) 3 17) 3 18) 2 19) 3 20) 1, , LEVEL -II (H.W) - KEY, 1., 2., 3., 4., 5., 6., 7., 8., 9., , Primary alcohol, Ketone, Invertase, Zymase, Primary alcohol does not give turbidity, immediately with Lucas reagent., Methyl alcohol, CH 4, More acidic, 30 > 20 > 10, tert. butyl alcohol, O, , 10. does not contain, , ||, −C − CH 3, , group, , 11. Chloroform, 12. CH 3COOH ; C2 H 5OH, 1) H 3 PO4 2) H 3 PO2 3) HPO3 4) H 3 PO3, 16. Which of the following is most suitable 13. Tertiary > Secondary > Primary, method for removing the traces of water from 15. H 3 PO3, ethanol ?, 16. Distillation, 1) Heating with Na metal, 17. 2-Butanol, 2) Passing dry HCl through it, 18. O - H, 3) Distilling it with CaO 4) Reacting with Mg 19. C H OSO H , C H OH, 2 5, 3, 2 5, 17. Which of the following compound gives 20. tert-butyl alcohol, ethylmethyl ketone on oxidation ?, PREVIOUS EAMCET QUESTIONS, 1) Propan -2-ol, 2) Butan -1-ol, 1. Identify the product in the following reaction, 3) Butan - 2-ol, 4) 2-methylbutan-2-ol, 18. In CH 3CH 2OH , the bond that undergoes heterolytic cleavage most readily in reaction with, ‘Na’ is, 1) C − C 2) O − H 3) C − H 4) C − O, 19. What are X and Y in the reaction, H 2O / ∆, 80 C, C2 H 4 + H 2 SO4 , → X , →Y, 0, , 1) C2 H 6 , C2 H 5OH, , 2) C2 H 2 , C2 H 5 SH, , 1), , 2), , 3), , 4), , 3) C2 H 5OSO3 H , C2 H 5OH 4) C2 H2 , CH3CHO, 20. Which one of the following contains, CSP 2 − OH bond ?, 1) vinyl alcohol, 3) benzyl alcohol, 58, , 2) allyl alcohol, 4) carbolic acid, , NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, 2., , Y, X , → Benzoquinone . Identify X and Y in, this reaction, , 7., , Which is the catalyst in the conversion of water, gas and hydrogen into methyl alcohol?, 1) MnO 2) raney Ni 3) Fe 4) ZnO-Cr2O3, , PROPERTIES, When ethyl alcohol is distilled with bleaching, powder and water then chloroform is, obtained. The no. of moles of bleaching, (X), (Y), (X), (Y), powder needed in the preparation of one mole, of chloroform is, 1) 10, 2) 5, 3) 4, 4) 2, 9. CH3OH + PCl3 → A, Zn, 4), 3., KCN, hydrolysis, Na2Cr2O7 / H 2 SO4, → B , , → C .Then "C" is, A , 2) CH3CHO, 1) CH3CH2OH, (X), (Y), (X), (Y), 3) CH3COOH, 4) CH2OH-CH2OH, 10. An organic liquid A containing H and O has, PREVIOUS EAMCET - KEY : 1) 2 2) 4, a pleasant odour with a boling point of 780C., On boiling A with conc. H2SO4 a colourless, gas is produced which decolourises bromine, LEVEL-III, water and alkaline KMnO4. One mole of this, NOMENCLATURE, gas also takes one mole of H2. The organic, 1. CH2OH—CHOH—CH2OH is glycerol., liquid A is, It doesn't contain ------------ alcoholic group, 1) C2H5Cl 2) C2H5CHO 3) C2H6 4) C2H5OH, 2) 20, 3) 30, 4) both 10 & 20, 1) 10, 11. A compound reacts with sodium and liberates, 2. An example for a polyhydric alcohol is, hydrogen and on oxidation gives ketone. The, 1) Methyl alcohol, 2) Neopentyl alcohol, formula of the compound could be., 3) Sec butyl alcohol 4) Mannitol, 1) CH3CH2OH, 2) CH3CHOHCH3, 3. Which one of the following is a secondary, 3)CH3CH2CH2OH, 4) CH3CH2 CH2CH2OH, alcohol, 12. Iodoform cannot be prepared from, 1) 2-methyl-2-propanol 2) 1-propanol, 1) CH 3OH, 2) C2 H 5OH, 3) 1-butanol, 4) 2-pentanol, 3) CH 3CHO, 4) CH 3COCH 3, PREPARATION, 4. Ethyl alcohol is manufactured from ethylene 13. I2 produced when ozone reacts with moist KI, is used to convert C 2H 5OH to CI 3CHO., by, Number of moles of ozone required to convert, 1) Permanganate, 2) Catalytic oxidation, 1 mole of C2H5OH into CI3CHO is, 3) Absorption into Conc. H2SO4 followed by, 1), 1, 2) 2, 3) 4, 4) 3, hydrolysis, 4) Reduction, 5. Which of the following pairs of the compounds 14. A compound "X" of the formula C3H8O gives, iodoform test. On oxidation with acidified, can be used as starting materials in the synthesis, K2Cr2O7, X gave Y. Y also gives iodoform, of 2-phenyl-2-pentanol?, test., Then X and Y are, 1) CH 3 (CH 2 )3 Br and PhCOOH, 1) CH3CH2CH2OH, CH3CH2CHO, 2) (CH 3 )2 CHCH 2 Br and PhCOCH 3, 2) CH3CHOHCH3 ,CH3COCH3, 3) CH3CH2CHO, CH3CH2CH2OH, 3) PhBr and CH 3CH 2CH 2COCH 3, 4) CH3COCH3, CH3CHOHCH3, 4) PhBr and (CH 3 )2 CHCH 2COCH 3, 15. In the Victor-Meyer’s test, red colouration is, 6. An enzyme which brings about the, shown by, conversion of starch into maltose is known, 1) 10 Alcohol, 2) 20 Alcohol, as, 1), , Na2Cr2O7 / H 2 SO4, , 2), , Zn, , 1) Diastase 2) Zymase 3) Maltase 4) Invertase, NARAYANAGROUP, , 8., , 3) 30 Alcohol, , 4) Phenol, 59
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , 16. When a mixture containing PCl3 and PCl5 is 9., heated with ethyl alcohol, a total of 4 moles of, ethyl chloride is formed. Mole ratio of PCl3, , 17., , 18., , 19., , 20., , and PCl5 in the mixture is, 1) 3 :1, 2) 1:1, 3) 1: 3, 4) 2 :1, When vapours of an alcohol are passed over, hot reduced copper, it gives an alkene. The, alcohol is, 1) Primary, 2) Secondary, 3) Tertiary, 4) None of these, When ethylhydrogen sulphate is heated with, excess of alcohol at 410K, the product obtained, is, 1) Ethane, 2) Ethylene, 3) Diethyl ether, 4) Diethyl sulphate, How many primary alcoholic isomers are, possibe for C5 H11OH ?, 1) 5, 2) 4, 3) 2, 4) 3, Methanol is industrially prepared by, 1) Oxidation of CH 4 by steam at 9000 C, , 12., , 14., 15., 16., 17., 18., 19., 20., 21., , 5., 6., 7., 8., , 1., , 60, , 2., , LEVEL-III - HINTS, HO − CH 2 − CH (OH ) − CH 2 − OH is glycerol., Mannitol is hexahydric alcohol, 2-pentanol, 3., It is an industrial method of preparation of ethyl, alcohol., Bromobenzene, Diastase, 4., ZnO −Cr2O3, CO + H 2 , → CH 3OH, , Four moles of bleaching power needed in the, prepration of one mole of chloroform, , group gives iodoform test, 4( O3 + 2 KI + H 2 O → 2 KOH + I 2 + O2 ), X= secondary alcohol ; Y= ketone, Primary alcohol, 1:1, Tertiary alcohol undergoes dehydration, Diethyl ether, based on the structure, from CO and H2, E1 mechanism, , LEVEL-IV, , LEVEL-III - KEY, , 1., 2., 3., 4., , (C ), , 13. C2 H 5OH + 4 I 2 → CI 3CHO + 5 HI, , This reaction takes place through, 1) S N 1 mechanism, 2) S N 2 mechanism, , 1) 3 2) 4 3) 4 4) 3 5) 3 6) 1 7) 4, 8) 3 9) 3 10) 4 11) 2 12) 1 13) 3 14) 2, 15) 1 16) 2 17) 3 18) 3 19) 2 20) 4 21) 3, , (B), , 11. 20 (or ) 30 alcohols on oxidation give ketone, , (CH 3 )3 C − OH → (CH 3 )2 C = CH 2 ;, , 4) E2 mechanism, , H 2O, , → CH 3CN , → CH 3COOH, , KMnO4, , H 2 SO4, , 3) E1 mechanism, , ( A), , KCN, , 10. C2 H 4 decolourises bromine water and alkaline, , 2) Reduction of HCHO using LiAlH 4, 3) Reaction HCHO with a solution of NaOH, 4) Reduction of CO using H 2 and ZnO − Cr2O3, 21., , PCl3, → CH 3Cl, CH 3OH , , 1) Both A and R are true and R is the correct, explanation to A, 2) Both A and R are true and R is not the correct, explanation to A, 3) A is true but R is false, 4) A is false but R is true, Assertion (A): In the fermentation process of, molasses, along with yeast (NH 4 ) 2 SO 4 ,, (NH4)3PO4 is added., Reason(R): (NH4)3PO4 and (NH4)2SO4, act as, food and helps the growth of yeast., Assertion (A): Alcoholic fermentation, involves conversion of sugar into ethanol by, the action of yeast., Reason(R): Fermentation involves the, liberation of CO2 gas., Assertion (A): Ethanol is miscible in all, proportions with water, Reason (R) : Hydrogen bond is formed, between water and alcohol molecules., Assertion (A): CaCl2 can’t be used for drying, ethyl alcohol, Reason (R) : Calcium chloride can form an, addition compound with ethyl alcohol, NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, 5., , 6., , 7., , 8., , Assertion (A): Ethyl alcohol is soluble in 12. Which of the following compounds on reaction, with CH3 Mg Br Will give a teritiary alcohol?, organic solvents, 2) HCHO, 1) C2H5 CHO, Reason (R) : Ethyl alcohol is having non polar, 3), C, H, COOH, 4) C2H5 COOCH3, ethyl group., 2 5, 13. 0.037g of an alcohol R-OH was added to, Assertion (A): The boiling point of C2H5OH, CH3MgBr and the gas evolved measured, is less than that of H2O though the molecular, 11.2ml at STP.The molecular mass of, weight of C2H5OH is more than that of water., R--OH will be, Reason (R) : C 2H5OH molecules are not, 1) 47, 2) 79, 3) 74, 4) 77, highly associated through hydrogen bonding, as water is, LEVEL-IV - KEY, Assertion (A): Dehydration of alcohols can be, 1) 1 2) 2 3) 1 4) 1 5) 1 6) 1 7) 2, carried out with Conc H2SO4 but not with, 8) 1 9) 2 10) 4 11) 3 12) 4 13) 3, conc.HCl., Reason (R) : H2SO4 is dibasic while HCl is, LEVEL-IV - HINTS, monobasic., 1. Ammonium phosphate and ammonium sulphate, act as food for yeast, Hydroboration-Oxidation of CH 3CH = CH 2, 2. Both are correct, produces., 3. Ethanol is a associated with water through, 1. CH 3CH 2CH 2OH, 2. CH 3CH (OH ) CH 3, hydrogen bond., 3. CH 3CH (OH ) CH 2OH 4. CH 3COCH 3, , 9., , The compound which gives the most stable, carbonium ion on dehydration., , 1), , CH 3, , CH, , CH2OH, , 2), , 4., 5., 6., 7., 8., , 9., 4), , 1. CH 3CH 2OH, , ( ), CH 3CH (OH ) CH 2CH 2CH 3 →, , CH 3COOH + CH 3CH 2COOH, , 11. A = CH 3CH 2CH (OH ) CH 3, B = CH 3CH = CHCH 3, , 2. CH 3CH (OH ) CH 2CH 3, , O, , 3. (CH 3 )2 C (OH ) CH 2CH 3, 4. CH 3CH (OH ) CH 2CH 2CH 3, , 30 carbanium ion is most stable., O, , 10. An alcohol on oxidation gives CH 3COOH and 10., CH 3CH 2COOH . The alcohol is, , 3, , 3 H 2 O2, , → CH 3CH 2 CH 2 OH + H 3 BO3, OH −, , CH 3, , 3) CH 3CH 2CH 2CH 2OH, , CaCl2 3C2 H 5OH, Ethyl alcohol is soluble in polar and non polar, solvents., Both are correct, with HCl R-Cl will form, BH inTHF, 3CH 3CH = CH 2 , → (CH 3CH 2CH 2 )3 B, , ||, , 12., , CH 3 MgBr, CH 3 − CH 2 − C − OCH 3 , →?, excess, , 11. An alcohol (A) on heating with concentarated 13. 11.2 ml of CH at STP is formed by 0.037 g of, 4, H 2 SO4 gives alkene (B) which can show the, R-OH, geometrical isomerism. The compound(A) is:, 22.400 ml CH 4 at STP .......?, 1) (CH3)2 C (OH) CH (CH3)2, 0.037 × 22, 400, 2) (CH3)2 C (OH) CH2 Me, =, = 74g of alcohol, 11.2, 3) CH3 CH2 CH (OH) CH3, 4) All of the above, NARAYANAGROUP, , 61
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , PREVIOUS MAINS QUESTIONS, 1., , Arrange the following compounds in order of, decreasing acidity, , 4., Product (A) is, O − Br, , OH, , 1), , 2), , CH 3 − CH − CH 2 − Br, , CH 3 − CH − CH 3, , O, , 3), 1) II > IV > I > III, 3) III > I > II > IV, , 2) I > II > III > IV, 4) IV > III > I > II, , 5., , CH 3 − C − CH 3, , 4) CH 3 − CH 2 − CH 3, , What is the major of the following reaction?, , PREVIOUS MAINS KEY : 1) 3, ADDITIONAL QUESTIONS, 1., , What is the structure of (C4 H10O ) which can, give positive haloform test and evolves, hydrogen gas with LiAlH 4 ., 1), , 1) CH 3 − CH 2 − O − CH 2 − CH 3, , 2), , CH 3, , 2), , CH 3 − CH − CH 2 − OH, , 3), , CH 3, , CH 3 − CH − CH 2 − CH 3, , 3), , CH 3 − C − OH, , 6., , 4), OH, CH 3, , 2., , The relative rates of reaction with, concentrated H 2 SO4 of the following is, , 4), , Which are not cleaved by HIO4 ?, I) glycerol, II) glycol, III)1, 3-propenediol, IV)methoxy-2-propanol, 1) I, II, III, IV, 2) I, II, 3) II, III, 4) III, IV, , I), 7., II), , 3., , III), , 1) I > II > III, 2) II > I > III, 3) I > III > II, 4) II > III > I, Which of the following is the best dehydrating, agent for 10 alcohols, 1) Con H 2 SO4 2) CaO 3) Al2O3 4) POCl3, , 62, , 1), , 2), , 3), , 4) No reaction, NARAYANAGROUP
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, , 2) 2-Phenyl-2-propanol 3) Acetophenone, 4) 2-Methyl-1-phenyl-2-propanol, 18. Which is the best reagent to convert isopropyl, alcohol to isopropyl bromide?, , 8., , CH 3, , CH 3, , 1), , 2), ?, → CH 3 − CH − Br, CH 3 − CH − OH , , 1) HBr, 2) SOBr2 3) Br2 4) CH 3 MgBr, 3), 4), 19. Choose the alcohol that is most reactive with, conc. HCl / ZnCl2 ?, 9. Which of the following alcohols is the least, 1) Methanol, 2) Ethanol, soluble in water?, 3) 2-propanol, 4) 2-methyl-2-propanol, 1) Ethanol 2) 1-Propanol 3) 1-Butanol 4) 1-Pentanol, 20. Treatment of 3-methyl-2-butanol with, 10. 3, 3-Dimethyl-2-butanol on reaction with, dry HCl gives, HCl yields mainly, 1) 2-Chloro-2, 3-dimethylbutane, 2) 1-Chloro-2, 3-dimethylbutane, 2), 1), 3) 2-Chloro-3, 3-dimethylbutane, 4) 1-Chloro-3, 3-dimethylbutane, 11. Propylene is subjected to hydroboration, oxidation reaction. The product formed, 3), 4), would be, 1)Propanal 2)1-Propanol 3)2-Propanol 4)Propanone, , 12. Ethylene glycol when heated in the presence 21. Glycol on treatment with PI 3 mainly gives, 1) Ethylene, 2) Ethylene iodide, of an hydrous ZnCl2 yields., 3) Ethyl iodide, 4) Ethane, 1) Ethanal, 2) Ethylene oxide, 22. Acrolein is formed when glycerol is heated, 3) Dioxane, 4) Diethylene glycol, with, 13. Clear orange solution of chromic anhydride, 1) Acidified KMnO4 2) Br2 water, in aqueous sulphuric acid turn blue-green on, reaction with, 4) HNO3, 3) KHSO4, 1) 3-Methyl-3-pentanol 2) 2-Butanol, 23. Glycerol on treatment with oxalic acid at, 3) 2-Methyl-2-propanol 4) 2-Methyl-2-butanol, 1100 C forms, 14. An organic compound ‘X; on treatment with, 1) Allyl alcohol, 2) Formic acid, acidified K 2Cr2O7 gives a compound ‘Y’ which, 4) Glyceric acid, 3) CO2 and CO, reacts with I 2 and sodium carbonate to form, 24. If the starting material is 1-methyl-1,, triodomethane. The compound ‘X’ could be, 2-epoxy cyclopentane, of absolute, 2) CH 3CHO, 1) CH 3OH, configuration, decide which one compound, correctly represent the product of its reaction, CH, CH, OH, CH, 3), ( ) 3 4) CH 3COCH 3, 3, with sodium methoxide in methanol., 15. Fusel oil is a mixture of, 1) Ethers, 2) alcohols, 3) Alcohols and ethers 4) Alcohols and ketones, 16. How many structuaral isomeric compounds, 2), 1), are possible for C4 H10O ?, 1) 4, 2) 5, 3) 6, 4) 7, 17., The compound Y in the above sequence is, 1) 2-Methyl-2-phenyl-1-propanol, NARAYANAGROUP, , 3), , 4), , 63
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ALCOHOLS, , JEE-MAIN-SR-CHEM-VOL-III, D) Oxidation of alkene into acid, S) P.C.C, , 25. Rate of hydration of, I), , II), , Reagent R, CH 3 − CH − CH = CH 2 , → Alcohol, , 30., , CH 3, , Which is true about alcohol and R?, Alcohol, Reagent, , III), , C H 3 − C H − C H 2 − C H 2O H, , will be in order;, 1) I<II<III 2) I<III<II 3) II<I<III 4) III<II<I, A), KHSO4, LiAlH 4, 26. Glycerol , → A , → B , A and B, are;, 1) Acrolein, allyl alcohol, 2) Glyceryl sulphate, acrylic acid, B), 3) Allyl alcohol, acrolein, 4) Only acrolein (B is not formed), , CH 3 − CH − CH − CH 3, , 27., , C H 3 − C − C H 2C H 3, , . In this dioal, , CH 3, , CH 3 OH, , PdCl2 , H 2O, O2 / LAH, , OH, , C), 1) OH at C2 is more basic than that of at C5, , B2 H 6 , H 2O2 / NaOH, , Hg (OAc )2 , H 2O / NaBH 4, , CH 3, , 2) OH at C2 is more acidic than at C5 ., OH, 3) both have same basic strength, 4) both have same acidic strength, C H 3 − C − C H 2C H 3, 28. Lucas test is used to make distinction between D), dil. H 2 SO4, 10 , 20 and 30 alcohols. This do not show that, CH 3, 1) ROH behaves as a base, ADDITIONAL QUESTIONS - KEY, 2) greater the value of pK a (alcohol), greater, the reactivity with conce. HCl and thus sooner, 1) 3 2) 4 3) 4 4) 3 5) 1 6) 4 7) 4, the formation of white turbidity., 8) 3 9) 4 10) 1 11) 1 12) 4 13) 2 14) 3, 3) alcohol which reacts fastest with Na metal,, 15) 2 16) 4 17) 3 18) 2 19) 4 20) 2 21) 1, will give turbidity at fastest rate, 22) 3 23) 2 24) 2 25) 1 26) 1 27) 1, 4) alcohol which gives red colour during Victor, 28) 1, 2, 4, Mayor test, will give turbidity ast slower rate, then those giving blue or white colour during, 29) (A) Q, R, S (B) S (C) Q (D) P 30) A, B, D, Victor Mayor test., ADDITIONAL QUESTIONS - HINTS, 29. Match the column:, 1., 2-hydroxy-2-alcohols responds to haloform, Column - I, Column - II, reaction, A) Oxidation of 10, 2. Stability of alkene in driving force, alcohols in aldehyde P) KMnO4 / ∆, 3. POCl2− is better leaving group, 4. NBS is oxidising agent, 5. H Θ attack on can less hindered side, B), Q) Collin’s reagent, 6. 1,2 diols oxidised by HIO4, 7. 30 alcohols do not undergoes oxidation, 9. as the Bulkyness increases solubility decreases, 10. 1, 2 alkyl shift, 11. anti markoniv’s addition of H 2O, R) Jone’s reagent, C), 13. 10 and 20 alcohols oxidised by K 2Cr2O7 / H +, 64, , NARAYANAGROUP