Tiêu đề UNIT 1 SOLUTIONS-1.pdf ✅

Page| 1 2.SOLUTIONS Single Correct Answer Type 1. A super saturated solution is a metastable state of solution in which solute concentration. a) Is equal to the solubility of that substance in water b) Exceeds than its solubility c) Less than its solubility d) Continuously change 2. Colligative properties of a solution depends upon a) Nature of both solvent and solute b) Nature of solute only c) Number of solvent particles d) The number of solute particles 3. The partition coefficient of solute X in between immiscible liquids A and B is 10 in favour of A. The partition coefficient of X in favour of B is : a) 0.1 b) 10 c) 0.01 d) 100 4. Which one is a colligative property? a) Raoult’s law states that the vapour pressure of a component over a solution is proportional to its mole fraction b) The osmotic pressure (π)of a solution is given by the equation π = MRT, where , M is the molarity of the solution c) The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl2 > KCl > CH3COOH > sucrose d) Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression 5. At25∘C , the highest osmotic pressure is exhibited by 0.1 M solution of a) Urea b) Glucose c) KCl d) CaCl2 6. The vapour pressure of two liquids X and Y are 80 and 60 Torr respectively. The total vapour pressure of the ideal solution obtained by mixing 3 moles of X and 2 moles of Y would be a) 68 Torr b) 140 Torr c) 48 Torr d) 72 Torr 7. Dilute 1 L one molar H2SO4 solution by 5 L water, the normality of that solution is a) 0.33 N b) 33.0 N c) 0.11 N d) 11.0 N 8. Solution A contains 7 g/L of MgCl2 and solution B contains 7 g/L of NaCl. At room temperature, the osmotic pressure of a) Solution A is greater than B b) Both have same osmotic pressure c) Solution B is greater than A d) Cannot be determine
Page| 2 9. Which one of the following aqueous solutions will exhibit highest boiling point? a) 0.01 M Na2SO4 b) 0.01 M KNO3 c) 0.015 M urea d) 0.015 M glucose 10. The modal elevation constant of water is 0.52°C. The boiling point of 1.0 modal aqueous KCl solution (assuming complete dissociation of KCl), therefore, should be a) 98.96°C b) 100.52°C c) 101.04°C d) 107.01°C 11. The increase in boiling point of a solution containing 0.6 g urea in 200 g water is 0.50∘C.Find the molal elevation constant. a) 10 K kg mol −1 b) 10 K g mol −1 c) 10 K kg mol d) 1.0 K kg mol −1 12. Which is correct representation of phase rule? a) F = P + C + 2 b) F + P = C + 2 c) F + C = P + 2 d) None of these 13. 40% by weight solution will contain how much mass of the solute in 1L solution, density of the solution is 1.2 g/mL? a) 480 g b) 48 g c) 38 g d) 380 g 14. 20 g of binary electrolyte (mol. wt. =100) are dissolved in 500 g of water. The depression in freezing point of the solution is 0.74°C (kf = 1.86 Km−1 ) the degree of ionisation of the electrolyte is a) 0% b) 100% c) 75% d) 50% 15. What is the molality of pure water? a) 1 b) 18 c) 55.5 d) None of these 16. Iodine was added to a system of water and CS2. The concentrations of iodine in water and CS2 were found to be c1andc2 respectively. The ratio c1/c2 will not change only if : a) More iodine is added b) More water is added c) More CS2 is added d) The temperature is changed 17. Which of the following associated with isotonic solutions is not correct? a) They will have the same osmotic pressure b) They will have the same vapour pressure c) They have same weight concentrations d) Osmosis does not take place when the two solutions are separated by a semipermeable membrane 18. The freezing point (in °C)of a solution containing 0.1 g of K3[Fe(CN)6] (mol.wt.329) in 100 g of water is : (Kf = 1.86 K kgmol −1 ) a) −2.3 × 10−2 b) −5.7 × 10−2 c) −5.7 × 10−3 d) −1.2 × 10−2
Page| 3 19. The Henry’s law constant for the solubility of N2 gas in water at 298 K is 1.0 × 105 atm. The mole fraction of N2 In air is 0.8 The number of moles of N2 from air dissolved in 10 moles of water of 298 K and 5 atm pressure is a) 4 × 10−4 b) 4.0 × 10−5 c) 5.0 × 10−4 d) 4.0 × 10−6 20. Van’t Hoff factor more than unity indicates that the solute in solution has a) Dissociated b) Associated c) Both (a) and (b) d) Cannot say anything 21. The condition for the validity of Henry’s law are : a) The pressure should not be too high b) The temperature should not be too low c) The gas should neither dissociate not enter into chemical combination with solvent d) All of the above 22. In an osmotic pressure measurement experiment, a 5% solution of compound ‘X’ is found to be isotonic with a 2 % acetic acid solution . The gram molecular mass of ‘X’ is a) 24 b) 60 c) 150 d) 300 23. Which is a colligativeproperty ? a) Osmotic pressure b) Free energy c) Heat of vaporisation d) Change in pressure 24. Kf for water is 1.86 K-kg-mol −1 . If your automobile radiator holds 1.0 kg of water, how many grams of ethylene glycol (C2H6O2) must you add to get the freezing point of the solution lowered to −2.8°C? a) 93 g b) 39 g c) 27 g d) 72 g 25. Vapour pressure of a solvent containing non-volatile solute is : a) More than the vapour pressure of a solvent b) Less than the vapour pressure of solvent c) Equal to the vapour pressure of solvent d) None of the above 26. Among the following mixtures, dipole-dipole as the major interaction is present in : a) Benzene and ethanol b) KCl and water c) Acetonitrile and acetone d) Benzene and CCl4 27. The vapour pressure of water depends upon : a) Surface area of container b) Volume of container c) Temperature
Page| 4 d) All of these 28. Which of the following solution highest boiling point? a) 0.1 M urea b) 0.1 M sucrose c) 0.1 M NaNO3 d) 0.1 M Al(NO3)3 29. At certain temperature a 5.12% solution of cane sugar is isotonic with a 0.9% solution of an unknown solute. The molar mass of solute is a) 60 b) 46.17 c) 120 d) 90 30. A mixture of ethane and ethene occupies 41 L at 1 atm and 500 K. the mixture reacts completely with 10 3 mole of O2 to produce CO2and H2O. The mole fraction of ethane and ethene in the mixture are (R = 0.082L atm K −1mol−1 ) respectively a) 0.50, 0.50 b) 0.75, 0.25 c) 0.67, 0.33 d) 0.25, 0.75 31. If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water (∆Tf), when 0.01 mole of sodium sulphate is dissolved in 1 kg of water, is (kf = 1.86 Kkg mol −1 ) a) 0.0372 K b) 0.0558 K c) 0.0744 L d) 0.0186 K 32. 2.5 L of NaCl solution contain 5 moles of the solute.What is the molarity ? a) 5M b) 2M c) 2.5M d) 12.5M 33. If for a sucrose solution elevation in boiling point is 0.1°C then what will be boiling point of NaCl solution for the same molal concentration? a) 0.1 b) 0.2 c) 0.16 d) 0.26 34. In two solutions having different osmotic pressure, the solution of higher osmotic pressure is called : a) Isotonic solution b) Hypertonic solution c) Hypotonic solution d) None of these 35. Isotonic solution have the same a) Normality b) Density c) Molar concentration d) None of these 36. Vapour pressure of pure A = 100 torr, moles = 2; vapour pressure of pure B=80 torr, moles = 3. Total vapour pressure of the mixture is a) 440 torr b) 460torr c) 180 torr d) 88 torr 37. Which of the following is incorrect? a) Relative lowering of vapour pressure is independent of the solute and the solvent. b) The relative lowering of vapour pressure is a colligative property. c) Vapour pressure of a solution is lower than the vapour pressure of the solvent. d) The relative lowering of vapour pressure is directly proportional to the original pressure.