Chapter 16 Solution 1. IF Hg,Cl, is 100% ionised then its van't Hoff factor will be (2 (4 @) 6 (4) 3 2. Lowering of vapour pressure for 1m aqueous solution is 1.08 mm of Hg at 25°C. The vapour Pressure of pure liquid at 25°C is 10x mm of Hg. The value of x will be, assuming very dilute solution (1) 4 (2) 6 @) 8 4) 3 3. How many terms will have negative value for a solution showing -ve deviation ? Ayr ASpigs AHgie AV, (1) 2 3 (3) 4 4) 1 4. Dry Air ‘Moist Air The above set up has been repeated four times with 4 different aqueous solution of same non-volatile solute with different concentrations. The loss in weight of solution in container is in order D > B > C > A: Arrange A, B,C, D in terms of concentration of solute (1) D>B>C>A Q) A>B>C>D @) A>C>B>D (4) A>D>C>B Azeotropic mixture of water and C, 361K. By distilling the mixture, obtain (1) Pure C,H,OH only (2) Pure water only (3) Both water and C,H,OH in pure state (4) Neither C,H,OH nor water Consider 0.1 M solution of two solutes X and Y. Solute X dissociates in two ions whereas Y dimerises in the solution. Which of the following is false ? (X and Y represents solution containing X and Y respectively) |,OH boils at is possible to (1) (AT) > (AT), (2) (B-P), >(B-P), @) (F-P),>(F-P), (4) (AT), >(AT)y An ideal solution was found to have a vapour pressure of 80 torr when the mole fraction of non- volatile solute is 0.2. Find vapour pressure of pure solvent at same temperature. (1) 64 torr (2) 72 torr (3) 80 torr (4) 100 torr The freezing point of a 4% (wiv) aqueous solution of ‘A’ is equal to the freezing point of 10% (wiv) ‘aqueous solution of ‘8’. The molecular weight of A is 60, find out the molecular weight of B, Assume both A and B are non electrolyte and molarity = molality (1) 160 (2) 90 (3) 45 (4) 180 When mercuric iodide is added to the aqueous solution of Kl, then the : (1) Freezing point is raised (2) Freezing point is lowered (3) Freezing point does not change (4) Bolling point does not change10. tt. 12. 13. 14, 16 Henry law constant of No in water is 10¢ atm. Find the molality (Approx) of N, in water when pressure of N, over water surface is 5 atm (consider temperature remains constant) (2) 0.028 (4) 0.12 Vapour pressure of a solvent is decreased by 10 mm of Hg. When a non-volatile, non-electrolytic solute was added. Mole fraction of the solute in solution is 0.2. Find out mole fraction of the solute if decrease in vapour pressure is 20 mm of Hg : (1) 04 (2) 0.2 @) 04 (4) 0.3 ‘The pair of solutions which show -ve devi Raoult's law is : (1) CCl, + CHCl, (1) 0.10 (@) 0.05 cl Br ob.d (8) H,0 + HNO, ° W CO) Hc Son," = Two solutions of glucose have osmotic pressure 1.5 aim and 2.5 atm respectively. 1 lit of first sol is mixed with 2 lit. of second solution at the same temperature. Then the osmotic pressure of resultant solution will be : (1) 2.16 atm 2) 3.5 atm (3) 5.12 atm (4) 7.2 atm Which one of the following solution boiling point ? (considering Molality = (1) 0.2 (M) Aqueous NaCl solution (2) 0.5 (M) Aqueous Glucose solution has highest Molarity) (8) 0.3 (M) Aqueous CaCl, solution (4) 0.2 (M) Aqueous urea solution What is a7, for 0.2 molal aqueous solution of urea? (K, of H,O'= 0.52) (1) 0.104 k (3) 0.506 K (2) 101.04 K (4) 5.08 K 19, 20. 24 7. 18. 16. The value of van't Hoff factor for K,[Fe(CN),), if it is 20 % ionised is 5 @ 4 (3) 1.8 (4) 1 Sugar sélution water is water ‘The two beakers are inside a jar as shown and kept for a long duration. Then (1) Mass of sugar solution will increase (2) Mass of sugar solution will decrease (3) Mass of H,0 in the right hand beaker will increase (4) No change in mass of either beaker Relative lowering of vapour pressure produced in a solution in which mole fraction of solvent is 0.7 is at (2) 0.7 3) 0.3 (4) 05 Which of the following physical quantity is not zero for an ideal solution? (1) AB pixng 2) AS pricing 8) AV ising (4) All of these Which one of the following form maximum boiling point azeotrope ? (1) CHCl, + C,H,OH (2) Ethanol + water (8) Benzene + toluene (4) HCI + water Relative lowering in vapour pressure of a solution containing 1 mole K,SO, in 54g HzO is (K,SO, is 100% ionised) 7 () 35 @ 55 3 1 OG >22. 23. 24. 25. 26. In the following graph, vapour pressure Is potled against mole fraction of the components. Which of the following statement is correct ? Le wa 8 Pena pressure Soar HX ne (Mole fraction of) (1) AD represents variation of vapour pressure of liquid A with xp, (2) BC represents variation of vapour pressure of liquid B with x3 (3) GH + FH = EH (4) All of these Henry's law constant for O, and Nz are Ko, = 3.3 107, Ky, = 66 * 107 x, fe Calculate ratio of %~, Le, the ratio of mole fraction Ne of O, and Np dissolved in water at 25°C assuming that air contains 80% Nz and 20% O, by volume (1) 0.62 (2) 0.92 (3) 0.42 (4) 0.5 The solubility of which of the following substances will decrease with increase of temperature ? (4) Calcite (2) Na,CO, (3) Na,SO, (4) All of these Which of the following will not show positive deviation ? (1) Ethyl alcohol and cyclohexane (2) CCl, and CHCl, (3) n-butane and n-pentane (4) CH,COCH, and aniline For which of the solvent K, has the highest value ? (1) Benzene (CgH,) (2) Water (H,0) (3) CCl, (4) Camphor (C4gH4g0) 28. 29. 30. 31. 32. Which of the following statements is/are correct for the above graph ? (1) BC shows variation of vapour pressure of pure solvent with temperature (2) D represent freezing point of solution (@) AB corresponds to the vapour pressure of solid at different temperature (4) All of these Vapour pressure of a pure solvent is 200mm Hg. If 2 mole of @ non volatile solute is mixed in 8 mole of solvent, the relative lowering of vapour pressure will be (1) 0.2 (@) 0.6 The solubility of a specific non volatile salt is high at 25°C. If 2gm, 4gm and 6gm of the salt added to 100gm at 25°C, the vapour pressure X.Y,Z (respectively) will follow the order of (1) XY=Z (2) Xe¥>z (3) YX (4) X= Henry law constant for N, in water at 25°C is 2x10* atm. Mass of N, in 500mL water at 1atm pressure at 25°C is: (1) 2.4%10-8g (2) 1.4x10-%g (3) 1.4%10%g (4) 3.9%10%9 Which of the following aqueous solution has highest boiling point? (1) 0.02 M NaCl (2) 0.05 M sucrose (3) 0.005 M Cacl, (4) 0.02 M CaCl, A complex is represented as CoCl,.xNH,, Its 0.1 molar solution in water shows melting point — 0.558K. (K, of H,0=1.86 K molality). Assuming 100% ionization of complex and coordination number of Co is 6, formula of complex is (1) (Co(NH,),CIICl, (2) [Co(NH,),ICI, (3) [Co(NH,),C1,]CI (4) All of these (2) 04 (4) 08 Zz4a. For (a) positive deviation solution, enthalpy change is (1) AH=0 (2) AH>0 @) aH <0 (4) All of these 34, Amount of ice that will separate out on cooling a solution containing 50 g ethelene glycol in 200 gm water to ~ 9.3°C will be (K, water = 1,86 K kg molt) (1) 38.7 9 (2) 3879 (@) 83.7.9 (4) 8.37 9 36, The temperature at which 10% aqueous solution (W/ V) of glucose will exhibit the osmotic pressure of 16.4 atm is [R = 0.082 dm? atm K-' mol] (1) 360K (2) 180k (3) 90K (4) 300 K 36. Find the amount of urea that should be dissolved in 100g of water in order to reduce its vapour pressure by 25% (1) 83.33g Q) 111.11g @) 18.519 (4) 45g 37. At 40°C, the vapour pressure of pure liquids, benzene and toluene are 160 mm Hg and 60 mm Hg respectively. At the same temperature, the vapour pressure of an equimolar solution of two liquids, assuming the ideal solution should be (1) 140 mm Hg (2) 110 mm Hg (3) 220 mm Hg (4) 100 mm Hg 38. K,, for H, (g) / water system is 5.34%107 torr. If the partial pressure of H, over a solution at 25°C is 760 torr, then determine the solubility of hydrogen. Assume density of H,O and solutions are same (1) 6.4 x 10% mol L~" (2) 7.89 x 104 mol L* (8) 5.9 x 103 mol L* (4) 8.9 x 104 mol L 38, ‘An aqueous solution of glucose boils at 100.01°C. Molal elevation constant of water 0.5 K molality-'. Find number of moles of glucose ‘mn 1009 water (1) 110? mole (2) 1*40 mole @) 210-9 mote (4) 3x10 mole 40. Select from the following that has highest osmotic pressure (1) 0.4. N urea (3) 0.1 N Na,SO, 2) 0. N Naci (4) 0.1 N Na,Po, 41. For a solution containing a non-volatile, non- electrolytic solute the relative lowering in vapour pressure is 0.2. If total number of moles present in the solution is 5, then which of the following is correct 7 (1) Mol fraction of solvent, Xsoiyent = 0.8 (2) Mol fraction of solute, Xsojo = 0.8 (3) Number of moles of solute = 4 (4) Number of moles of solvent = 2 42. Two pure liquids A and B have vapour pressures in the ratio 1 : 3. The mol fraction of ‘A’ in vapour phase, when A and B are mixed in 1 : 3 molar ratio in a solution, will be (1) 04 2) 02 @) 03 4) 05 43. Consider the following graph, depicting the variation of total vapour pressure and vapour pressure of ‘components of a solution with mol fraction. ig vp. Pa % %=1 (mol fraction) Which of the following is correct regarding the plot? (1) Ais more volatile than B (2) 8 will be more in liquid phase starting from equal mole fractions of ‘A’ and ‘B’ (3) AD = BD + CD (4) AD = BC + CD 44, A gas exerts a partial pressure of 0.2 atm over water. The Henrys’ law constant is 104 atm. The solubility of the gas in millimol per litre will be approximately (1) 2.75 x 10° (2) 1.1 x 103 8) 4.1 « 105 (4) 2.75 x 10-4 45. If a saturated solution of potassium nitrate is heated (1) tt becomes unsaturated (2) It becomes super saturated (3) It remains saturated (4) Crystallization occurs46. If an ideal solution is produced by mixing components A and B, then which of the following is correct? (1) AG pig = 0 (2) BHpyix = 9 3) AG pic = 9+ ASmix = © (4) Sm = © 47. For which of the following binary mixtures, AHprix > 0? (1) C,HgCl + C)HsBr (2) CxHgOH + CH;-CO-CH, (3) H,0 + HNO, (4) CHCl, + CHy - CO - CH, For a mixture of HCI and water, the following statements are written 48. (a) The solution exhibits negative deviation from Raoult’s law (b) The solution boils at a temperature higher than those of either components (©) The solution is an example of maximum boiling azeotrope The correct statement(s) is/are (1) (@) and (b) (2) (c) only (3) (@) and (c) (4) (a), (b) and (c) The ebullioscopic constant for a solvent is 0.5 K molal-?. The 19 point of a solution containing 0.05 mole of a non-volatile, non-electrolytic solute in 0.25 kg solvent will increase by (1) 10K @ 1K 3) 01K (4) 100 K 50. Which of the following solutions will have highest freezing point ? (1) 0.1 M KCI (2) 0.1 M BaCl, (3) 0.1 M FeCl, (4) 0.1 M Fe(S0,), 51. In case of osmosis, solvent moves from 49. (1) Higher vapour pressure region to lower vapour pressure region (2) Higher concentration to lower concentration (3) Lower vapour pressure region to higher vapour pressure region (4) Higher osmotic pressure region to lower osmotic pressure region 52, 53. 55. 56. 87. 58. The vapour pressure of a solution of a non-volatile solute B in solvent A mixed in 2 : 5 molar ratio is 250 mm. Considering ideality, calculate the vapour pressure of a solution prepared by mixing B and A in the ratio 3 : 4 (1) 200 mm of Hg (2) 300 mm of Hg (3) 150 mm of Hg (4) 375 mm of Hg ‘An equimolar solution of two volatile liquids A (M = 450 g mol") and B (M = 200 g mot) has vapour pressure 500 torr. If vapour pressure of pure B is ‘400 torr, the mol fraction of component A in vapour phase is, (1) 0.5 (2) 0.6 (3) 0.3 (4) 0.4 Which of the following is true with respect to Henry's law ? (1) With increase in pressure of the gas, it's solubility increases (2) It is obeyed by gases at low temperature and high pressure (3) With increase in temperature the value of Henrys’ law constant decreases (4) All of these For a solution with negative deviations which of the following is true ? (1) AGpig <0, AS py > 0 (2) AH pig < 0s AVpxig <0 3) AG pig <0, ASprig < 0 (4) Both (1) and (2) Which of the following binary solutions exhibits negative deviations from Raoult’s law ? (1) Acetone + Ethanol (2) Pyridine (3) Acetone + Carbon disulphide (4) Cyclohexane + Ethanol B.P. of Azeotropic mixture of HNO, and H,0 is, (if B.P of HINO, is x and B.P of HO is y) (1) Greater than y 2 a @) Less than x (4) 7 An element ‘X' exists as a polymer X,. When 3.2 9 of X is dissolved in 200 g of a solvent (K, = 5 K molal-*), the freezing point is lowered by 0.125°C. The molecular formula of X,, is (Atomic wt of X = 80) (1) % 2% @% (4) %59. A 5.25% wiv solution of an unknown solute is 60. a 2, 3, 64 65, 6, isotonic with a 1.5% w/v solutios n of urea at constant temperature and in the same solvent. Assuming equal densities of both the solution, calculate the molecular mass of the unknown solute (1) 90 (2) 105 @ 115 (4) 210 Which one is/are correct 2 Statement 1: Molar mass of polymer is determined by osmotic pressure Method Statement Il: Mixture of CCI, + Toluene is positive deviation solution Statement Ill : During formation of positive deviation solution heat is absorbed ‘Statement IV : Upon addition of L,(s) in aqeous KI solution, B.P increases (1) 1, Ill, IV only 2) 1, (3) 1, It only. (4) 1, mV Which of the following will have the same value of Van't Hoff factor as that of K,[Fe(CN).]? (Assume equal degree of dissociation) (1) Na,SO, (2) AKINOs) 8) Ala(SO4)3 (4) KglFe(CN),) Calculate the Van't Hoff factor (i) of K, (Fe(CN),] which is 80% ionised (1) 1.4 (2) 28 @) 32 (4) 42 Which of the following is not associated with ideal solution? (1) Age = 0 2) ASpu = 0 (3) AVppig = 0 (4) AG pig <0 IFP, is osmotic pressure of 0.1 M KCI and P, is ‘osmotic pressure of 0.1 M acetic acid then (1) Py > P, 2) P,> Pp @) P,=P, (4) P,=0 The total vapour pressure of solution obtained by ‘mixing 3 mole of P and 2 mole of Q is 72 torr. The Pure vapour pressure of liquid P is 80 torr. The pure vapour pressure of liquid Q is (1) 80 torr (2) 60 torr 3) 40 torr (4) 20 torr Which has minimum freezing point? (1) 1 motar Nac! solution (2) 1 motar KC! solution (3) 1 molar glucose solution () 1 molar CaCl, solution 67. 68. 69. 70. m1. 72. Which of the following is correct? (1) The solubility of a gas in water increases with increase of temperature (2) The solubility of a gas in water increases with increase of pressure (3) Higher the value of Ky, at a particular pressure, higher is the solubility of the gas in the liquid (4) Henry's law is valid if the gas reacts chemically with the solvent and dissociates or associates in the solvent 5 mol of solvent along with 2 mol of a non-volatile solute exhibit vapour pressure = 250 mm ng. If we make a mixture containing 4 mol of the same solvent and 3 mol of the same solute, then what would be vapour pressure now? (1) 300 mm ug (2) 200 mm ug (3) 225 mm yg (4) 275 mm ug The following plot best represents i solubility Temperature —> (1) Nact (2) NaNo, (3) Na,SO,.10H,0 (4) Cac, Which of the following combinations is correct for a binary solution ? (1) CgHe and CoHeCHy ; AggH > 0; AsV = 0 a @) CH,-8-CH, and CHO: Aga <0; Asal <0 (8) HO and HCI; AsgH > 0; AggV <0 (4) HO and CHjOH ; AjgH <0; Aggy < 0 The depression in freezing point of 0.01m aqueous CHCOOH solution is 0.02046°. 1m urea solution freezes al ~1.86°C. Assuming molality equal to molarity, pH of CH,COOH solution is (1) 2 23 3) 3.2 (4) 4.2 Choose the correct statement (1) Calcium acetate shows decrease in solubility with rise in temperature Solubility of KNO,, NaNO, decreases with rise in temperature Solubility of gases increases with increase in temperature Vapour pressure depends on volume of the vessel in which liquid - vapour equilibrium is established. 2) @) (4)73. An aqueous solution freezes at —0.186°C (K = 1.86Kkgmol~!, K, = 0.512Kkgmol~). The elevation of boiling point of the solution is (in K) (1) 0.186 ( 0512 512 © “36 (4) 0.0512 74. Osmotic pressure of a sucrose solution is 4.926 atm at 27°C. Which of the following is not isotonic with the given solution ? (1) 3.6% glucose solution (2) 1.2% urea solution (3) 0.585% NaC! solution (4) 1.7% NaNO, solution 75. A B o1M NH, (2q.) o1M Cu” (aq.) ‘S.P.M. In which of the following compartment, Blue colour of [Cu(NH,),* will be observed first 7 (1) A compartment (2) B compartment (8) Blue colour will be observed at same time in both compartment (4) None of these compartment shows blue colour 76. Which of the following point represents Azeotropic Mixture concentration ? Ma 2) B ac 4) 0 77. 78. 79. 80. at. 82. 83. 84, nA=A, if a is the degree of association, what will be the value of van't Hoff factor (i) ? (1) 14+ (n= 1)a (2) 4 3) tease (4) 1-0 What will be the osmotic pressure of 0.2 MHX (aq.) solution at 300K ? {K,(HX) = 8 * 10%] (2) 5.024 atm (4) 1.813 atm (1) 3.926 atm (8) 7.124 atm ‘According to Henry's law, the solubility of 2 gas in fa given volume of liquid increasing with increase in (2) Pressure (3) Henry Constant (K,) (4) Both (1) and (2) Which of the following property will have the same sign of value for ideal solution and solution showing the deviation ? [K,(H,0) = 0.52 K kg mot) (1) Temperature (1) AGpues BHpues ASpix (2) AVps AS pee (3) ASyue1 AGree (4) AV ics AGrux 0.1 Molal aqueous solution of an electrolyte AB, is 90% ionized. The boiling point of solution at 1 atm is [K,(H,0) = 0.52K.kg.mol") (1) 273.19K (2) 274.92K (3) 374.92K (4) 373.19K 24 g of C,0;H, is dissolved in 100 g water, in order to produce ice, mixture is cooled to ~10°C, if K, = 1.86, the amount of ice (in g) separated (1) 25.6 (2) 50.5 (8) 75.6 (4) 20.8 The total vapour pressure of a solution of methanol and ethanol in an ideal solution is given by P = 1350 + 100 (where & = mole fraction of methanol). Pure state vapour pressure of methanol is (1) 235 mm yg (2) 100 mm yg (3) 35 mm pg (4) 135 mm yg Henry's constant for Ar is 40 kbar in water. Then ‘molal concentration of Ar in water kept at 10 bar pressure will be : (1) 0.09 (3) 1.25 (2) 0.05 (4) 0.014gs. A mixture 86. of benzene and toluene have a vapour pressure of 290 mm of Hg at 300K. The vapour pressure of toluene is 200 mm of Hg. If the mole fraction of benzene is 0.6 then its vapour pressure in pure form at same temperature will be (1) 700 mm of Hg (2) 300 mm of Hg (@) 350 mm of Hg (4) 200 mm of Hg Which one pair of compounds will exhibit +ve deviation from Raoult’s law ? (1) H,0 + HNO, (2) (CH,),CO + CHCI, (3) C,H,OH + H,0 (4) CH,COOH + C,H,N (Pyridine) Qa 87. 28. Elevation of boiling point was found to be 0.52°C, When 8g of a compound (Nonvolatile, Nonelectrolyte) was dissolved in 200g of water then molar mass of the compound will be : {Given K,(H,0) : 0.52 Kkg molt] (1) 50 (2) 100 (3) 40 (4) 30 Which of the following aqueous solution is having highest freezing point ? [Assume : Molarty ~ Molaliy] (1) 0.01 (M) KCI (2) 0.005 (M) CaCl, (3) 0.01 (M) Na,So, (4) 0.005 (M) Glucose a(4) () (1) (4) 2) 2) (8) () (4) 2) @) (2) 8) (2) (1) @) (4) (4) (2) 2) () (@) 2) (1) (2) Chapter 16 : Solution @) (4) (4) 8) 8) 4. a 18. 25. 32. 39. 46. 53. 60. 67. 74. 81 88. @) 8) @) (4) (1) 6) @) 2) @) 2) (4) 4) (4) (4) 8) @) (4) @ (2) (2) () (8) (2) (4) (1) 20. zy. 34. 41. 62. 69. 76. 83. @) (1) (4) (4) () (1) (4) 4) 4) (3) (3) (1) ay 28. 42. 49. 56. 63. 70. 77. (4) 8) (4) () (4) (4) 8) @) (2) @) 8) @)