Question 1

Which of the following best describes a supersaturated solution?

Accepted Answer

A solution that contains more solute than is stable at a given temperature, and will precipitate solute if disturbed.

Question 2

Which of the following compounds would be most soluble in water?

Accepted Answer

Ethanol ($$\mathrm{C_2H_5OH})$$

Question 3

A can of soda is opened at room temperature. According to Henry’s Law, what happens to the solubility of CO$$_2 in $$the soda?

Accepted Answer

It decreases because the pressure above the liquid decreases.

Question 4

Which of the following best explains why oil and water do not mix?

Accepted Answer

Oil and water have different polarities, leading to weak intermolecular interactions between them.

Question 5

Which equation correctly expresses Henry’s Law for the solubility of a gas in a liquid?

Accepted Answer

$$S_{\mathrm{gas}} = k_{\mathrm{gas}} P_{\mathrm{gas}}$$

Question 6

Which of the following statements about colligative properties is TRUE?

Accepted Answer

They depend only on the number of solute particles present.

Question 7

A solution is prepared by dissolving 1.00 mol of NaCl in 1.00 kg of water. What is the expected van’t Hoff factor ($$i) $$for NaCl?

Accepted Answer

$$i = 2$$

Question 8

Which of the following best describes the effect of adding a non-volatile solute to a solvent?

Accepted Answer

It decreases the vapour pressure of the solvent.

Question 9

Calculate the boiling point elevation for a solution made by dissolving 0.50 mol of NaCl in 1.00 kg of water. ($$K_b = 0.512\ ^\circ\mathrm{C}\,\mathrm{kg}/\mathrm{mol}$$, assume $$i = 2)$$

Accepted Answer

$$\Delta T_b = 0.512$$ $$^\circ\mathrm{C}\,\mathrm{kg}/\mathrm{mol} 	imes 0.50\,\mathrm{mol/kg} 	imes 2 = 0.512$$ $$^\circ\mathrm{C}$$

Question 10

Which of the following is a real-world application of supercritical fluids?

Accepted Answer

Decaffeinating coffee using supercritical CO$$_2$$

Question 11

Which of the following best explains why the boiling point of water is lower on Mt. Everest than at sea level?

Accepted Answer

The atmospheric pressure is lower, so water boils at a lower temperature.

Question 12

Which of the following best describes the process of osmosis?

Accepted Answer

Solvent molecules move through a semi-permeable membrane to equalize concentration.

Question 13

A solution is prepared by dissolving 0.385 g of cholesterol ($$\mathrm{C$$_{27}$$H_{46}O$$}$$) in 40.0 g of chloroform ($$\mathrm{$$CHCl_3$$}$). What is the molality of the solution? (Molar mass of cholesterol = 386 g/mol)

Accepted Answer

$$0.0250\ \mathrm{mol/kg}$$

Question 14

Which of the following is the correct formula for osmotic pressure?

Accepted Answer

$$\pi = iCRT$$

Question 15

Which of the following best describes an azeotrope?

Accepted Answer

A mixture that boils at a constant temperature and cannot be separated by simple distillation.

Question 16

Which of the following statements about the van’t Hoff factor ($$i) is $$correct?

Accepted Answer

It is the number of ions produced per formula unit of solute dissolved.

Question 17

Which of the following best explains why adding salt to ice causes it to melt?

Accepted Answer

Salt lowers the freezing point of water, causing ice to melt at lower temperatures.

Question 18

Which of the following is a colligative property?

Accepted Answer

Boiling point elevation

Question 19

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

Accepted Answer

Solubility decreases as temperature increases.

Solutions and Phase Behavior in General Chemistry

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