Q: A solution is prepared by mixing 0.6 mole fraction of benzene (vapor pressure = 268 mmHg at 50°C) and 0.4 mole fraction of ethylene chloride (vapor pressure = 236 mmHg at 50°C). What is the total vapor pressure of the solution at 50°C?

$$P_{total} = 268 \times 0.6 + 236 \times 0.4 = 255.2$$ mmHg

Question 1

Which of the following best explains why sucrose (table sugar) dissolves readily in water?

Accepted Answer

Sucrose molecules have several O-H bonds that form hydrogen bonds with water molecules.

Question 2

Which of the following statements about the solvation process is CORRECT?

Accepted Answer

Solvation is the process of surrounding solute particles with solvent particles to form a solution.

Question 3

A solid dissolves in a liquid in a process where the lattice energy is greater than the solvation energy. What can you conclude about the dissolution process?

Accepted Answer

The dissolution process is endothermic.

Question 4

Which equation correctly represents the total enthalpy change when a solution forms?

Accepted Answer

$$\Delta H_{soln} = \Delta H_{solute} + \Delta H_{solvent} + \Delta H_{mix}$$

Question 5

Which of the following best describes the effect of temperature on the solubility of gases in liquids?

Accepted Answer

Solubility of gases in liquids decreases with increasing temperature.

Question 6

Raoult's law for an ideal solution of two volatile liquids A and B is given by:

Accepted Answer

$$P_{total} = X_A P_A^0$ + X_B P_B^0$

Question 7

A solution is prepared by mixing 0.6 mole fraction of benzene (vapor pressure = 268 mmHg at 50°C) and 0.4 mole fraction of ethylene chloride (vapor pressure = 236 mmHg at 50°C). What is the total vapor pressure of the solution at 50°C?

Accepted Answer

$$P_{total} = 268 	imes 0.6 + 236 	imes 0.4 = 255.2$$ mmHg

Question 8

Which of the following pairs of liquids will form a completely miscible solution?

Accepted Answer

Benzene and toluene

Question 9

Which of the following statements about partially miscible liquids is TRUE?

Accepted Answer

They separate into two layers after saturation, each layer containing some of both liquids.

Question 10

The critical solution temperature ($$T_c) $$for a pair of partially miscible liquids is:

Accepted Answer

The temperature above which the two liquids are completely miscible in all proportions.

Question 11

Which of the following best describes the effect of pressure on the solubility of gases in solids?

Accepted Answer

Solubility of gases in solids increases with increasing pressure.

Question 12

Which of the following is NOT a characteristic of an ideal solution?

Accepted Answer

The solution shows a large deviation from Raoult's law.

Question 13

A student observes that the solubility of a solid increases with temperature. What can be inferred about the dissolution process?

Accepted Answer

The dissolution process is endothermic ($$\Delta H \u003e 0).$$

Question 14

Which of the following best describes the difference between adsorption and absorption in the context of gases in solids?

Accepted Answer

Adsorption is keeping gas on the surface, absorption is keeping gas inside the solid.

Question 15

Which of the following is a correct application of the 'like dissolves like' principle?

Accepted Answer

Polar solutes dissolve best in polar solvents.

Question 16

A solution is formed by mixing two liquids, A and B. The attractive forces between A and B are much weaker than those between A-A and B-B. What type of solution is most likely formed?

Accepted Answer

A completely immiscible solution

Question 17

Which of the following best explains why the solubility of most solids increases with temperature?

Accepted Answer

Dissolution of solids is generally endothermic, so increased temperature supplies the energy needed.

Question 18

In the context of Raoult's law, what does $$X_A$$ represent in the equation $$P_A = X_A P_A^0$?

Accepted Answer

The mole fraction of component A in the solution

Question 19

Which of the following is a real-life example of a partially miscible liquid pair?

Accepted Answer

Water and phenol

Solution Chemistry: Types, Mechanisms, and Properties

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