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A binary solution of liquids A and B deviates positively from Raoult's law. Which of the following statements is NOT true for this solution?
The total vapour pressure of the solution is greater than the ideal vapour pressure.
The intermolecular forces between A-A and B-B are stronger than those between A-B.
The enthalpy of mixing () is positive.
The volume of mixing () is positive.
At a given temperature, the vapour pressure of pure liquid A is 300 mmHg and that of pure liquid B is 500 mmHg. A solution of A and B shows a total vapour pressure of 400 mmHg. Assuming ideal behavior, what is the mole fraction of A in the liquid phase?
0.2
0.5
0.8
1.0
A solution containing a non-volatile solute exhibits a lower vapor pressure than the pure solvent. This phenomenon can be BEST explained by:
The solute particles increase the intermolecular forces between solvent molecules.
The solute particles decrease the kinetic energy of the solvent molecules.
The solute particles occupy some surface area, reducing the solvent's ability to evaporate.
The solute particles react with the solvent molecules, reducing the amount of solvent available.
Which one of the following is TRUE for a solution showing negative deviation from Raoult's law?
A-B interactions are weaker than A-A and B-B interactions
A binary solution of two volatile liquids A and B deviates negatively from Raoult's Law. At a specific composition, the total vapor pressure is minimum. Which of the following statements is FALSE regarding this specific composition?
The vapor and liquid phases have identical compositions.
The boiling point is higher than that of either pure A or pure B.
The system deviates negatively from Raoult's Law.
The mole fraction of A in the vapor is always greater than that of B.
A solution containing a non-volatile solute exhibits a vapor pressure lowering of 20 mm Hg compared to the pure solvent. If the mole fraction of the solute is 0.2, what is the vapor pressure of the pure solvent in mm Hg?
80 mm Hg
100 mm Hg
120 mm Hg
20 mm Hg
Two liquids A and B form an ideal solution. At a certain temperature, the vapor pressure of pure A is 400 mm Hg and that of pure B is 700 mm Hg. If the mole fraction of A in the liquid phase is 0.4, what is the mole fraction of A in the vapor phase?
0.276
0.571
0.724
0.420
Which statement BEST describes the relationship between Raoult's and Henry's Laws?
Henry's Law is applicable for all solutions, while Raoult's Law is only for ideal solutions.
Raoult's Law is a special case of Henry's Law where the Henry's law constant equals the vapor pressure of the pure component.
Henry's Law describes the behavior of the solute in a dilute solution, while Raoult's Law describes the behavior of the solvent.
Both laws are only applicable to solutions of non-volatile solutes.
A solution is prepared by dissolving 1.8 g of a non-volatile solute in 90 g of water. The vapor pressure of the solution is found to be 23.375 mm Hg at 25°C. If the vapor pressure of pure water at 25°C is 23.76 mm Hg, what is the molar mass of the solute? (Molar mass of water = 18 g/mol)
60 g/mol
180 g/mol
30 g/mol
120 g/mol
A solution of glucose (C6H12O6) is prepared by dissolving 18g of glucose in 90g of water at 300K. If the vapour pressure of pure water at 300K is 31.82 mm Hg, what is the vapour pressure of the solution?
31.19 mm Hg
31.82 mm Hg
30.55 mm Hg
32.45 mm Hg
