Grade 12 : Chemistry - Solutions (Set 3)

Question 1

A solution of liquid A and liquid B exhibits positive deviation from Raoult's Law. Which statement best describes the intermolecular forces in this solution?

Accepted Answer

B) A-B interactions are weaker than A-A and B-B interactions.

Answer

A) A-B interactions are stronger than A-A and B-B interactions.

Answer

C) A-B interactions are equal to A-A and B-B interactions.

Answer

D) The solution forms an azeotrope with maximum boiling point.

Question 2

If 0.1 mol of glucose (C6H12O6, a non-electrolyte) and 0.1 mol of sodium chloride (NaCl, a strong electrolyte) are separately dissolved in 1 kg of water, which solution will have a higher boiling point?

Accepted Answer

B) Sodium chloride solution

Answer

A) Glucose solution

Answer

C) Both will have the same boiling point

Answer

D) The boiling point depends on the solvent's specific heat capacity.

Question 3

Two solutions, P and Q, are separated by a semipermeable membrane. Solution P has a higher concentration of solute than solution Q. In which direction will the net flow of solvent occur due to osmosis?

Accepted Answer

B) From Q to P

Answer

A) From P to Q

Answer

C) No net flow will occur, only solute diffusion.

Answer

D) The flow direction depends on the molecular weight of the solute.

Question 4

Which set of conditions would increase the solubility of a gas in a liquid solvent?

Accepted Answer

D) Decreasing temperature and increasing pressure.

Answer

A) Increasing temperature and decreasing pressure.

Answer

B) Decreasing temperature and decreasing pressure.

Answer

C) Increasing temperature and increasing pressure.

Question 5

Why is molality preferred over molarity for expressing concentration in experiments involving significant temperature changes?

Accepted Answer

C) Molality depends on the mass of the solvent, which is temperature-independent.

Answer

A) Molality is easier to calculate and requires less precise measurements.

Answer

B) Molality depends on the volume of the solution, which changes with temperature.

Answer

D) Molarity is a less accurate measure of concentration at any temperature.

Question 6

A weak electrolyte AB partially dissociates in water. If its degree of dissociation is $\alpha$, what is the van't Hoff factor ($i$)?

Accepted Answer

A) $1 + \alpha$

Answer

B) $1 - \alpha$

Answer

C) $1 + 2\alpha$

Answer

D) $1 - 2\alpha$

Question 7

An azeotrope is a binary mixture that:

Accepted Answer

B) Boils at a constant temperature and distills without change in composition.

Answer

A) Shows ideal behavior and strictly obeys Raoult's law.

Answer

C) Always has a higher boiling point than either pure component.

Answer

D) Always has a lower boiling point than either pure component.

Question 8

If the partial pressure of a gas above a liquid solvent is doubled, what happens to its solubility in that solvent, assuming constant temperature?

Accepted Answer

B) It doubles.

Answer

A) It remains the same.

Answer

C) It halves.

Answer

D) It quadruples.

Question 9

Which of the following colligative properties is independent of the nature of the solute, given it's non-volatile and a non-electrolyte?

Accepted Answer

D) All of the above

Answer

A) Vapor pressure lowering

Answer

B) Osmotic pressure

Answer

C) Boiling point elevation

Question 10

A 100 g sample of water is found to contain 0.005 g of a contaminant. What is the concentration of the contaminant in parts per million (ppm)?

Accepted Answer

C) 50 ppm

Answer

A) 0.5 ppm

Answer

B) 5 ppm

Answer

D) 500 ppm