JEE Main - Raoult's law ideal and non-ideal solutions and vapour pressure composition Online Test (MCQ Quiz)

1. According to Raoult's law, for a solution of non-volatile solutes, the relative lowering of vapour pressure is equal to:

A) The mole fraction of the solvent B) The mole fraction of the solute C) The number of moles of the solute D) The number of moles of the solvent

2. Which of the following statements is true for an ideal solution?

A) ΔHmix = 0, ΔVmix = 0 B) ΔHmix ≠ 0, ΔVmix = 0 C) ΔHmix = 0, ΔVmix ≠ 0 D) ΔHmix ≠ 0, ΔVmix ≠ 0

3. For a binary solution, Raoult's law states that the partial vapour pressure of each volatile component is equal to:

A) Its mole fraction in the solution multiplied by its vapour pressure in the pure state B) Its mole fraction in the vapour phase multiplied by its vapour pressure in the pure state C) Its concentration in the solution multiplied by its vapour pressure in the pure state D) Its molality in the solution multiplied by its vapour pressure in the pure state

4. A solution that obeys Raoult's law over the entire range of concentration is called:

A) Non-ideal solution B) Ideal solution C) Azeotrope D) Dilute solution

5. Which property of a solution is directly proportional to the mole fraction of the solute for non-volatile solutes, according to Raoult's Law?

A) Boiling point elevation B) Freezing point depression C) Relative lowering of vapour pressure D) Osmotic pressure

6. If a solution shows positive deviation from Raoult's law, then:

A) Intermolecular forces between solute-solvent are stronger than between like molecules B) Intermolecular forces between solute-solvent are weaker than between like molecules C) ΔHmix is negative D) ΔVmix is negative

7. For a binary solution of components A and B, if P_A and P_B are partial vapour pressures and x_A and x_B are mole fractions, Raoult's law can be expressed as:

A) P_A = x_A * P_A° and P_B = x_B * P_B° B) P_A = x_B * P_A° and P_B = x_A * P_B° C) P_A = x_A * P_B° and P_B = x_B * P_A° D) P_A = x_A + P_A° and P_B = x_B + P_B°

8. Which of the following is a characteristic of a non-ideal solution showing negative deviation?

A) Vapour pressure is higher than predicted by Raoult's law B) Boiling point is lower than predicted by Raoult's law C) Formation of solution is endothermic (ΔHmix > 0) D) Volume of solution is greater than the sum of volumes of pure components (ΔVmix > 0)

9. The total vapour pressure of a solution containing volatile components A and B is given by:

A) P_total = P_A° + P_B° B) P_total = x_A * P_A° + x_B * P_B° C) P_total = x_A * P_B° + x_B * P_A° D) P_total = P_A + P_B

10. A solution that deviates from Raoult's law is called:

A) Ideal solution B) Azeotropic mixture C) Non-ideal solution D) Colloidal solution

11. If the vapour pressure of a solution is lower than predicted by Raoult's law, it indicates:

A) Positive deviation B) Negative deviation C) Ideal behaviour D) No deviation

12. In a binary ideal solution, the sum of mole fractions of the components is always:

A) Zero B) Less than one C) Equal to one D) Greater than one

13. Which of the following pairs forms an ideal solution?

A) Water and Ethanol B) Benzene and Toluene C) Acetone and Chloroform D) Water and HCl

14. A solution where the solute-solvent interactions are stronger than solute-solute and solvent-solvent interactions exhibits:

A) Positive deviation from Raoult's law B) Negative deviation from Raoult's law C) Ideal behaviour D) No deviation from Raoult's law

15. The vapour pressure composition curve for a non-ideal solution showing positive deviation is:

A) A straight line B) A curve below the straight line C) A curve above the straight line D) An inverted curve

16. Which phenomenon occurs when a solution does not obey Raoult's law and forms a mixture with a constant boiling point?

A) Osmosis B) Diffusion C) Azeotrope formation D) Crystallization

17. For a solution of a non-volatile solute in a volatile solvent, the vapour pressure of the solution is:

A) Equal to the vapour pressure of the pure solvent B) Less than the vapour pressure of the pure solvent C) Greater than the vapour pressure of the pure solvent D) Dependent on the concentration of the solute only

18. If P_total is the total vapour pressure of a solution of volatile components A and B, and x_A, x_B are their mole fractions in the liquid phase, then according to Dalton's law of partial pressures and Raoult's law, P_total is:

A) x_A * P_A° B) x_B * P_B° C) x_A * P_A° + x_B * P_B° D) x_A * P_B° + x_B * P_A°

19. Which of the following conditions favors the formation of an ideal solution?

A) Strong solute-solvent interactions B) Weak solute-solvent interactions C) Similar molecular size and polarity of components D) Dissimilar molecular size and polarity of components

20. A solution shows negative deviation from Raoult's law when:

A) ΔHmix > 0 and ΔVmix > 0 B) ΔHmix < 0 and ΔVmix < 0 C) ΔHmix = 0 and ΔVmix = 0 D) ΔHmix > 0 and ΔVmix < 0

21. The vapour pressure of a pure solvent is denoted by:

A) P_solute B) P_solvent C) P° D) P_solution

22. Which of the following is a non-ideal solution showing minimum boiling azeotrope?

A) Nitric acid and water B) Ethanol and water C) Hydrochloric acid and water D) Acetone and benzene

23. In a mixture of two volatile liquids A and B, if the mole fraction of A in the vapour phase is higher than its mole fraction in the liquid phase, it indicates:

A) A is less volatile than B B) A is more volatile than B C) A and B are ideal components D) A and B form an azeotrope

24. Raoult's law is a special case of:

A) Henry's law B) Dalton's law of partial pressures C) Avogadro's law D) Gay-Lussac's law

25. For a binary solution, the vapour pressure composition curve for an ideal solution is:

A) A non-linear curve B) A curve that lies above the straight line C) A straight line D) A curve that lies below the straight line

26. Which of the following is a characteristic of a solution exhibiting positive deviation from Raoult's law?

A) ΔHmix < 0 B) ΔVmix < 0 C) Vapour pressure is lower than predicted D) Vapour pressure is higher than predicted

27. The vapour pressure of a solution containing a non-volatile solute at a given temperature is always:

A) Equal to the vapour pressure of the pure solvent B) Less than the vapour pressure of the pure solvent C) Greater than the vapour pressure of the pure solvent D) Dependent on the nature of the solute

28. A solution that shows negative deviation from Raoult's law will have:

A) Weaker solute-solvent interactions than pure components B) Stronger solute-solvent interactions than pure components C) Equal solute-solvent interactions as pure components D) No interaction between solute and solvent

29. When two volatile liquids are mixed, the total vapour pressure will be the sum of partial vapour pressures, as per:

A) Raoult's law B) Dalton's law of partial pressures C) Henry's law D) Avogadro's law

30. An example of a solution exhibiting negative deviation from Raoult's law is:

A) Benzene and Toluene B) Ethanol and Water C) Acetone and Chloroform D) n-Hexane and n-Heptane

31. If the mole fraction of solvent in a solution is 0.8 and the vapour pressure of the pure solvent is 100 mmHg, what is the vapour pressure of the solution assuming it behaves ideally and the solute is non-volatile?

A) 100 mmHg B) 80 mmHg C) 20 mmHg D) 0 mmHg

32. What is the mole fraction of the solute if the relative lowering of vapour pressure is 0.2 and the solution is ideal?

A) 0.2 B) 0.8 C) 1.0 D) 0.0

33. Which of the following statements is incorrect regarding non-ideal solutions?

A) They do not obey Raoult's law B) They may show positive or negative deviations C) For negative deviation, ΔHmix is always positive D) For positive deviation, ΔVmix is usually positive

34. The vapour pressure of a mixture of two volatile liquids A and B is given by P_total = x_A * P_A° + x_B * P_B°, where x_A and x_B are mole fractions in the liquid phase. This represents:

A) A non-ideal solution B) An ideal solution C) A solution showing negative deviation D) A solution showing positive deviation

35. A solution that boils at a constant temperature and has the same composition in the liquid and vapour phases is called:

A) A regular solution B) An ideal solution C) An azeotrope D) A supersaturated solution

36. If a solution shows positive deviation, the boiling point of the solution will be:

A) Higher than that of the pure components B) Lower than that of the pure components C) Equal to that of the pure components D) Unpredictable

37. The vapour pressure of component A in a binary solution is given by P_A = x_A * P_A°. This implies:

A) Component A obeys Henry's law B) Component A is non-volatile C) Component A obeys Raoult's law D) Component A forms an ideal solution with the solvent

38. Which of the following is a characteristic of a solution showing negative deviation from Raoult's law?

A) Interactions between solvent and solute molecules are weaker than between solvent-solvent or solute-solute molecules. B) Volume of the solution is greater than the sum of the volumes of the pure components. C) The formation of the solution is an endothermic process. D) The solution has a lower vapour pressure than predicted by Raoult's law.

39. The vapour pressure of a mixture of two volatile liquids A and B is represented by a curve that lies below the straight line connecting P_A° and P_B°. This indicates:

A) Ideal behaviour B) Positive deviation C) Negative deviation D) Formation of an azeotrope

40. If P_A° > P_B°, and in the vapour phase, the mole fraction of A (y_A) is greater than its mole fraction in the liquid phase (x_A), then:

A) A is less volatile than B B) A is more volatile than B C) A and B are ideal components D) y_A = x_A

41. According to Raoult's law, the relative lowering of vapour pressure of a solvent is equal to the mole fraction of the:

A) Solvent in the solution B) Solute in the solution C) Solvent in the vapour phase D) Solute in the vapour phase

42. Which of the following is a characteristic of a solution showing positive deviation from Raoult's law?

A) ΔHmix < 0 B) ΔVmix < 0 C) Solute-solvent interactions are stronger than pure component interactions D) Solute-solvent interactions are weaker than pure component interactions

43. A solution that forms a maximum boiling azeotrope will exhibit:

A) Positive deviation from Raoult's law B) Negative deviation from Raoult's law C) Ideal behavior D) No deviation from Raoult's law

44. For a binary solution of volatile components A and B, if the vapour pressure composition curve lies above the straight line connecting P_A° and P_B°, it indicates:

A) Negative deviation B) Ideal behavior C) Positive deviation D) Formation of an azeotrope

45. In a non-ideal solution showing negative deviation, the volume of the solution is generally:

A) Greater than the sum of the volumes of the pure components B) Less than the sum of the volumes of the pure components C) Equal to the sum of the volumes of the pure components D) Unpredictable

46. Raoult's law is applicable to:

A) Dilute solutions only B) Concentrated solutions only C) Ideal solutions D) Non-ideal solutions

47. If the vapour pressure of a solution is equal to the vapour pressure of the pure solvent, then the solute must be:

A) Volatile and forming an ideal solution B) Non-volatile C) Volatile and forming a non-ideal solution D) Present in zero concentration

48. Which of the following is a pair of liquids that does NOT form an ideal solution?

A) n-Hexane and n-Heptane B) Benzene and Toluene C) Water and Ethanol D) Carbon tetrachloride and Benzene

49. The total vapour pressure of a binary solution of volatile components A and B can be expressed as P_total = x_A * P_A° + (1-x_A) * P_B° only if:

A) The solution shows positive deviation B) The solution shows negative deviation C) The solution is ideal D) The solution forms an azeotrope

Raoult's law ideal and non-ideal solutions and vapour pressure composition - Online Test

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