Solutions Mock Test – Class 12 Chemistry

1. For tetramerisation with degree of association , the value of is:

2. Assertion: Molarity can change when the temperature of a solution changes.
Reason: Molarity uses volume of solution in its denominator, and liquid volume can expand or contract with temperature.

3. A student calculates molar mass from osmotic pressure using instead of , while is in . The main error is:

4. Assertion: Relative lowering of vapour pressure is a colligative property.
Reason: It depends on the number of solute particles through solute mole fraction, not on the chemical identity of the solute in ideal dilute behaviour.

5. In reverse osmosis used for desalination, the semipermeable membrane mainly allows:

6. A hot saturated solution of is cooled carefully without disturbance and remains clear, even though its concentration is higher than the normal solubility at the lower temperature. The solution is:

7. The missing conversion in the statement “ ______ ” is:

8. In the formula , the symbol is:

9. A solubility value is reported as solute per water at . If solute is mixed with water at , the solution formed is:

10. A comparison table is shown below.

The row that needs correction is:

11. Two solutions separated by a semipermeable membrane are isotonic when they have:

12. For a solute that dissociates as , the maximum possible value of is:

13. A student has three data sets for the same solute: with rise in boiling point, with lowering in freezing point, and . If all experiments are ideal and no association or dissociation occurs, the molar mass obtained should be:

14. The situation-relation pairing that is mismatched is:

15. An observed van't Hoff factor is . Which interpretation is most reasonable?

16. In the standard classification table of solutions, an amalgam of mercury with sodium is best classified as:

17. Gas mixtures used for deep-sea diving are chosen carefully because:

18. A saturated solution at is cooled to . The solubility of the solid is lower at . The most likely observation is:

19. A prepared solution is heated slightly, causing its volume to expand without changing the masses of solute and solvent. The pair of concentration terms expected to remain unchanged on this basis is:

20. The association result that is not consistent with the stated process is:

21. A gas chemically reacts with water after dissolving. A simple Henry's law calculation may fail because:

22. The osmotic pressure equation modified for association or dissociation is:

23. Observed boiling-point data for a solution give in a solvent with . The most suitable conclusion is:

24. Assertion: A semipermeable membrane is essential for osmosis.
Reason: Osmosis is defined as solvent movement through such a membrane from dilute solution toward concentrated solution.

25. A non-volatile nonelectrolyte is dissolved in a solvent. If the molality is doubled while the solvent remains the same, the boiling point elevation:

26. The terms dilute and concentrated mainly compare:

27. The vapour pressure of a pure liquid is the pressure exerted by:

28. A liquid mixture contains of ethanol and of water. The mole fraction of ethanol is:

29. A solution shows and . This observation most directly suggests:

30. A table gives four situations.

The row that needs correction is:

31. Match the example in Column I with the most suitable solute-solvent description in Column II.

32. Warm water usually holds less dissolved gas than cold water because:

33. Trimer formation gives . The degree of association is:

34. A red blood cell placed in a strongly hypertonic solution may shrink because:

35. A record for saturated solutions contains these statements.
Statement I: A saturated solution contains the maximum dissolved solute under stated conditions.
Statement II: In a saturated solution with undissolved solute present, dissolution and crystallisation can continue at equal rates.
Statement III: Once a solution is saturated at one temperature, it remains saturated at all temperatures.

36. An ideal solution has , , and . The total vapour pressure and vapour-phase mole fraction of are respectively:

37. Assertion: A true solution does not show settling of solute particles on standing.
Reason: In a true solution, the solute is uniformly distributed at molecular or ionic level.

38. A nonelectrolyte solution is at . Using , its osmotic pressure is:

39. When and are known, should be calculated using:

40. A weak electrolyte partially dissociates in water. Compared with a nonelectrolyte solution of the same formal concentration at the same temperature, its osmotic pressure is expected to be:

41. Complete trimerisation of a solute gives a van't Hoff factor of:

42. A sample of river water contains dissolved oxygen in water. Assuming water has mass close to , the dissolved oxygen concentration is approximately:

43. Abnormal molar mass obtained from a colligative property usually indicates that the solute:

44. A red blood cell placed in a hypotonic solution is likely to swell because:

45. Consider the following statements about true solutions.
Statement I: A true solution has uniform composition throughout.
Statement II: A true solution may be solid, liquid, or gas.
Statement III: A true solution must always be colourless.

46. A liquid mixture obeys Raoult's law over the composition range considered. For component , reducing from to at the same temperature will:

47. A non-volatile solute is dissolved in a volatile solvent. The solution has a lower vapour pressure than the pure solvent and exerts osmotic pressure across a semipermeable membrane. These observations are similar because both:

48. A solution is separated from a glucose solution by a semipermeable membrane at the same temperature. If is completely dissociated, the correct statement is:

49. A solution of a solute that associates as has observed osmotic pressure . The normal osmotic pressure calculated without association is . The degree of association is:

50. A student uses total solution mass instead of solvent mass while finding molar mass from . The main error is that: