MCQ
1. Which of the following units is useful in relating concentration of solution with its vapour pressure?
(a) Mole fraction (b) Parts per million (c) Mass percentage (d) Molality
2. On dissolving sugar in water at room temperature solution feels cool to touch. Under which of the following cases dissolution of sugar will be most rapid?
(a) Sugar crystals in cold water (b) Sugar crystals in hot water (c) Powdered sugar in cold water (d) Powdered sugar in hot water
3. At equilibrium the rate of dissolution of a solid solute in a volatile liquid solvent is ________.
(a) Less than the rate of crystallisation (b) Greater than the rate of crystallisation (c) Equal to the rate of crystallisation (d) Zero
4. A beaker contains a solution of substance ‘A’. Precipitation of substance ‘A’ takes place when small amount of ‘A’ is added to the solution. The solution is ___________.
(a) saturated (b) supersaturated (c) unsaturated (d) concentrated
5. Maximum amount of a solid solute that can be dissolved in a specified amount of a given liquid solvent does not depend upon ________.
(a) temperature (b) nature of solute (c) pressure(d) nature of solvent
6. Low concentration of oxygen in the blood and tissues of people living at high altitude is due to ________.
(a) Low temperature (b) Low atmospheric pressure (c) High atmospheric pressure (d) Both low temperature and high atmospheric pressure
7. Considering the formation, breaking and strength of hydrogen bond, predict which of the following mixtures will show a positive deviation from Raoult s law?
(a) Methanol and acetone (b) Chloroform and acetone (c) Nitric acid and water (d) Phenol and aniline
8. Colligative properties depend on _________.
(a) the nature of the solute particles dissolved in solution (b) the number of solute particles in solution (c) the physical properties of the solute particles dissolved in solution (d) the nature of solvent particles
9. Which of the following aqueous solutions should have the highest boiling point?
(a) 1.0 M NaOH (b) 1.0 M Na2SO4 (c) 1.0 M NH4NO3 (d) 1.0 M KNO3
10. The unit of ebullioscopic constant is _________.
(a) K kg mol-1 or K (molality)-1 (b) Mol kg K-1 or K-1 (molality) (c) Kg mol-1 K -1 or K-1 (molality)-1 (d) K mol kg-1 or K (molality)
11. In comparison to a 0.01 M solution of glucose, the depression in freezing point of a 0.01 M MgCl2 solution is
(a) the same (b) about twice (c) about three times (d) about six times.
12. An unripe mango placed in a concentrated salt solution to prepare pickle, shrivels because _________.
(a) It gains water due to osmosis (b) It loses water due to reverse osmosis (c) It gains water due to reverse osmosis (d) It loses water due to osmosis
13. At a given temperature, osmotic pressure of a concentrated solution of a substance ________.
(a) Is higher than that at a dilute solution (b) Is lower than that of a dilute solution (c) Is same as that of a dilute solution (d) Cannot be compared with osmotic pressure of dilute solution
14. The values of van’t Hoff factors for KCl, NaCl and K2SO4, respectively, are __________
(a) 2, 2 and 2 (b) 2, 2 and 3 (c) 1, 1 and 2 (d) 1, 1 and 1
15. Value of Henry’s constant KH __________.
(a) Increases with increase in temperature (b) Decreases with increase in temperature (c) Remains constant (d) First increases then decreases
16. Two beakers of capacity 500 mL were taken. One of these beakers, labelled as “A”, was filled with 400 mL water whereas the beaker labelled “B” was filled with 400 mL of 2 M solution of NaCl. At the same temperature both the beaker were placed in closed containers of same material and same capacity as shown in figure. At a given temperature, which of the following statements is correct about the vapour pressure of pure water and that of NaCl solution.
(a) Vapour pressure in container (A) is more than that in container (B).
(b) Vapour pressure in container (A) is less than that in container (B).
(c) Vapour pressure is equal in both the containers.
(d) Vapour pressure in container (B) is twice the vapour pressure in container (A).
17. We have three aqueous solutions of NaCl labelled as ‘A’, ‘B’ and ‘C’ with concentrations 0.1 M, 0.01 M and 0.001 M, respectively. The value of van’t Hoff factor for these solutions will be in the order
18. If two liquids A and B form minimum boiling azeotrope at some specific composition then _________.
(a) A – B interactions are stronger than those between A – A or B – B
(b) Vapour pressure of solution increases because more number of molecules of liquids A and B can escape from the solution
(c) Vapour pressure of solution decreases because less number of molecules of only one of the liquids escape from the solution
(d) A – B interactions are weaker than those
between A – A or B – B
19. 4 L of 0.02 M aqueous solution of NaCl was diluted by adding one litre of water. The molality of the resultant solution is ___________.
(a) 0.004 m (b) 0.008 m (c) 0.012 m (d) 0.016 m
20. KH values for Ar(g) , 2(g) (g) CO HCHO , and CH4(g) are 40.39, 1.67, 1.83 x 10-5 and 0.413 respectively. Arrange these gases in the order of their increasing solubility.
21. 50 mL of an aqueous solution of glucose C6H12O6 (Molar mass : 180 g/mol) contains 6.02 x 1022 molecules. The concentration of the solution will be [2020]
(a) 0.1 M (b) 0.2 M (c) 1.0 M (d) 2.0 M
22. On dissolving ammonium chloride in water at room temperature, the solution feels cool to touch. Under which of the following conditions does salt dissolve faster? [2023]
(a) Powdered salt in cold water (b) Powdered salt in hot water (c) Salt crystals in cold water (d) Salt crystals in hot water
23. Low concentration of oxygen in the blood and tissues of people living at high altitude is due to [2023]
(a) High atmospheric pressure (b) Low temperature (c) Low atmospheric pressure(d) Both low temperature and high atmospheric pressure
24. An unknown gas ‘X’ is dissolved in water at 2.5 bar pressure and has mole fraction 0.04 in solution. The mole fraction of ‘X’ gas when the pressure of gas is doubled at the same temperature is [Term I, 2021 – 22]
(a) 0.08 (b) 0.04 (c) 0.02 (d) 0.92
25. Which of the following formula represents Raoult’s law for a solution containing non-volatile solute? [Term I, 2021 – 22]
26. Which one of the following pairs will form an ideal solution?
(a) Chloroform and acetone (b) Ethanol and acetone (c) n-Hexane and n-heptane (d) Phenol and aniline
27. On mixing 20 mL of acetone with 30 mL of chloroform, the total volume of the solution is [Term I, 2021 – 22]
(a) < 50 mL (b) = 50 mL (c) > 50 mL (d) = 10 mL
28. An azeotropic solution of two liquids has a boiling point lower than either of the two when it
(a) shows a positive deviation from Raoult's law (b) shows a negative deviation from Raoult's law (c) shows no deviation from Raoult's law (d) is saturated.
[Term I, 2021 – 22]
29. The boiling point of a 0.2 m solution of a nonelectrolyte in water is [Term I, 2021 – 22]
(a) 1000C (b) 100.520C (c) 100.1040C (d) 100.260C
30. In the following diagram point ‘X’ represents [Term I, 2021 – 22]
(a) Boiling point of solution (b) Freezing point of solvent (c) Boiling point of solvent. (d) Freezing point of solution.
31. The colligative property used for the determination of molar mass of polymers and proteins is
(a) osmotic pressure (b) depression in freezing point (c) relative lowering in vapour pressure (c) elevation in boiling point. [2023]
32. Out of the following 1.0 M aqueous solutions which one will show largest freezing point depression? [2023]
(a) NaCl (b) Na2SO4 (c) C6H12O6 (d) Al2(SO4)3