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UNIT 2. SOLUTIONS, Annual Exam – 2014, 1., , Define the term ‘molarity’., , 1, , 2., , Mention the enthalpy of mixing (∆mixH) value to form an ideal solution., , 1, , 28. a) On dissolving 2.34 𝑔 of solute in 40 𝑔 of benzene, the boiling point of the solution was higher 3, than that of benzene by 0.81𝐾. 𝐾𝑏 value for benzene is 2.53 𝐾𝑘𝑔𝑚𝑜𝑙 −1 . Calculate the molar, mass of the solute., b) State Henry’s law. Write its mathematical form., , 2, , Supplementary Exam – 2014, 1., , Define the term ‘molarity’., , 1, , 2., , What is binary solution?, , 1, , 28. a) The vapour pressure of pure benzene at a certain temperature is 0.85bar. When 0.5g of a non- 3, volatile solute is added to 39g of benzene (molar mass = 78gmol-1), vapour pressure of the, solution is 0.845bar. What is the molar mass of a non-volatile solute?, b) What happens to the solubility of gas in a liquid with increase in temperature? Give reason., , 2, , Annual Exam – 2015, 1., , At a given temperature and pressure, nitrogen gas is more soluble in water than helium gas. 1, Which one of them has higher value of KH?, , 2., , On mixing equal volumes of acetone and ethanol, what type of deviation from Raoult’s law is 1, expected?, , 28. a) A solution containing 18𝑔 of non-volatile, non-electrolyte solute is dissolved in 200𝑔 of water, , 3, , freezes at 272.07𝐾. Calculate the molecular mass of solute. Given: 𝐾𝑓 = 1.86 𝐾𝑘𝑔𝑚𝑜𝑙 −1 ,, Freezing point of water = 273𝐾., b) Define isotonic solution. What happens when the blood cell is dipped in a solution containing, , 2, , more than normal saline concentration?, Supplementary Exam – 2015, 1., , On what factor the value of colligative property depends?, , 1, , 2., , Give an example for liquid solution in which solute is gas., , 1, , 28. a) The boiling point of benzene is 353.23𝐾. When 1.80𝑔 of a non-volatile, non-ionising solute 3, was dissolved in 90𝑔 of benzene, the boiling point is raised to 354.11𝐾. Calculate the molar, mass of the solute. (𝐾𝑏 for benzene = 2.53 𝐾𝑘𝑔𝑚𝑜𝑙 −1 ), b) Write two differences between ideal and non-ideal solutions., , 2, , Annual Exam – 2016, 1., , State Raoult’s law for liquid mixtures., , Dr. PRAVEEN B. KAJJARI, LECTURER, GOVERNMENT PU COLLEGE, DANDELI, , 1, Page 1

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2., , Define molality., , 1, , 28. a) 300 𝑐𝑚3 of an aqueous solution of a protein contains 1.26 𝑔 of the protein. The osmotic, , 3, , pressure of such a solution at 300K is found to be 2.57 × 10−3 𝑏𝑎𝑟. Calculate the molar mass, of the protein. (𝑅 = 0.083𝐿𝑏𝑎𝑟𝑚𝑜𝑙 −1 𝐾 −1 ), b) What are non-ideal solutions? Mention the reason for the negative deviation from the Raoult’s, , 2, , law., Annual ReExam – 2016, 1., , Name the law behind the dissolution of 𝐶𝑂2 gas in soft drinks under high pressure., , 1, , 2., , Ornamental gold containing copper is an example for what type of solution?, , 1, , 28. a) 5.8𝑔 of a non-volatile solute was dissolved in 100𝑔 of 𝐶𝑆2 (molar mass = 76𝑔𝑚𝑜𝑙 −1 ). The, , 3, , vapour pressure of the solution was found to be 190 𝑚𝑚 𝑜𝑓 𝐻𝑔. Calculate the molar mass of, the solute. Vapour pressure of pure 𝐶𝑆2 is 195𝑚𝑚 𝑜𝑓 𝐻𝑔., b) Write two differences between ideal and non-ideal solutions., , 2, , Supplementary Exam – 2016, 1., , State Henry’s law., , 1, , 2., , Soda water bottles are sealed under high pressure. Give reason., , 1, , 28. a) 300 𝑐𝑚3 of an aqueous solution of a protein contains 2.12 𝑔 of the protein, the osmotic 3, pressure of such a solution at 300 K is found to be 3.89 × 10−3 bar. Calculate the molar mass, of the protein. (𝑅 = 0.0823 𝐿 𝑏𝑎𝑟 𝑚𝑜𝑙 −1 𝐾 −1 ), b) What are ideal solutions?, , 1, , c) What is the effect of rise in temperature on the solubility of gases in liquids?, , 1, , Annual Exam – 2017, 1., , How does molarity vary with temperature?, , 1, , 2., , 10 mL of liquid ‘A’ is mixed with 10 mL of liquid ‘B’, the volume of the resultant solution is 1, 19.9 mL. What type of deviation is expected from Raoult’s law?, , 28. a) 1 g of non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene 3, by 0.4 K. Find the molar mass of the solute. [Given: Freezing point depression constant of, benzene = 5.12 𝐾𝑘𝑔𝑚𝑜𝑙 −1 ], b) How solubility of a gas in liquid varies with i) Temperature, , and, , ii) Pressure, , 2, , Supplementary exam – 2017, 1., , State Raoult’s law of a binary solutionsfor two volatile liquid components., , 1, , 2., , van’t Hoff factor for a solution is more than one. What is the conclusion drawn from it?, , 1, , 28. a) The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non- 3, electrolyte solid weighing 0.5 g, when added to 39.0 g of benzene (molar mass of benzene is 78, 𝑔 𝑚𝑜𝑙 −1 ), vapour pressure of the solution then is 0.845 bar. What is the molar mass of solid, Dr. PRAVEEN B. KAJJARI, LECTURER, GOVERNMENT PU COLLEGE, DANDELI, , Page 2

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substance?, b) What is reverse osmosis? Mention its one practical utility., , 2, , Annual Exam – 2018, 1., , State Henry’s law., , 1, , 2., , van’t Hoff factor for a solution is less than one. What is the conclusion drawn from it?, , 1, , 28. a) The boiling point of benzene is 353.23𝐾. When 1.80𝑔 of a non-volatile, non-ionising solute 3, was dissolved in 90𝑔 of benzene, the boiling point is raised to 354.11𝐾. Calculate the molar, mass of the solute. (𝐾𝑏 for benzene = 2.53 𝐾𝑘𝑔𝑚𝑜𝑙 −1 ), b) Define i) Molality of a solution ii)Isotonic solutions, , 2, , Supplementary Exam – 2018, 1., , State Henry’s law., , 2., , In a binary solution, mole fraction of one component is 0.068. What is the mole fraction of 1, , 1, , other component?, 28. a) 5.8𝑔 of a non-volatile solute was dissolved in 100𝑔 of 𝐶𝑆2 (molar mass = 76𝑔𝑚𝑜𝑙 −1 ). The 3, vapour pressure of the solution was found to be 190 𝑚𝑚 𝑜𝑓 𝐻𝑔. Calculate the molar mass of, the solute. Vapour pressure of pure 𝐶𝑆2 is 195𝑚𝑚 𝑜𝑓 𝐻𝑔., b) Mention any two difference between ideal and non-ideal solutions., , 2, , Annual Exam – 2019, 1., , How does the size of the blood cells changes when placed in and aqueous solution containing 1, more than 0.9 % (w/v) sodium chloride?, , 2., , How does the volume changes on mixing two volatile liquids to form an ideal solution?, , 1, , 28. a) 31 g of an unknown molecular material is dissolved in 500g of water. The resulting solution 3, freezes at 271.14 K. Calculate the molar mass of the material[Given: for water 𝐾𝑓 =, 1.86 𝐾𝑘𝑔𝑚𝑜𝑙 −1 , 𝑇𝑓𝑜 = 273 K], b) What is reverse osmosis? Mention its use., , 2, , Supplementary Exam – 2019, 1., , Write the unit of molality of a solution?, , 1, , 2., , At a given temperature, oxygen gas is more soluble in water than nitrogen gas. Which one of 1, them has higher value of 𝐾𝐻 ?, , 28. a) On dissolving 2.34 g of non-electrolyte solute in 40 g of benzene, the boiling point of solution 3, was higher than benzene by 0.81 K. 𝐾𝑏 for benzene is 2.53 𝐾𝑘𝑔𝑚𝑜𝑙 −1 . Calculate the molar, mass of the solute.[ Molar mass of benzene is 78 𝑔𝑚𝑜𝑙 −1 ]., b) i) State Henry’s law., , 2, , ii) How solubility of a gas in liquid changes with increase in temperature?, Annual Exam – 2020, Dr. PRAVEEN B. KAJJARI, LECTURER, GOVERNMENT PU COLLEGE, DANDELI, , Page 3

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1., , What is the value of Van’t Hoff factor (i) for 𝐾2 𝑆𝑂4 ?, , 2., , 10 mL of liquid ‘A’ is mixed with 10 mL of liquid ‘B’, the volume of the resultant solution is 1, , 1, , 19.9 mL. What type of deviation is expected from Raoult’s law?, 28. a) Vapour pressure of benzene is 200 mm of Hg. When 2 gram of a non-volatile solute dissolved 3, in 78 gram of benzene. Benzene has vapour pressure of 195 mm of Hg. Calculate the molar, mass of the solute. [molar mass of benzene is 78 𝑔𝑟𝑎𝑚𝑚𝑜𝑙 −1 ], b) What are azeotropes? Give example for binary solutions showing minimum boiling azeotrope., , 2, , Supplementary Exam – 2020, 1., , Define molality., , 1, , 2., , The 𝐾𝐻 values for nitrogen gas (𝑁2 ) at 293 K and 303 K are 76.48 kbar and 88.84 kbar 1, respectively. Among these two given temperatures, at which temperature nitrogen gas is more, soluble in water?, , 28. a) 1.00 g of a non-electrolyte solute is dissolved in 50 g of benzene lowers the freezing point of 3, benzene by 0.4 K. The freezing point depression constant for benzene is 5.12 𝐾𝑘𝑔𝑚𝑜𝑙 −1 . Find, the molar mass of the solute., c) State Henry’s law. Write its mathematical form., , Dr. PRAVEEN B. KAJJARI, LECTURER, GOVERNMENT PU COLLEGE, DANDELI, , 2, , Page 4