Q: A solution is made by dissolving 13.5 g of glucose (C$$_6H$_{12}O$_6) in 0.100 kg of $$water. What is the mass percentage of glucose in the solution?

$$\frac{13.5}{13.5+100} \times 100 = 11.9\%$$

Q: A solution is made by dissolving 4.35 g of glucose (C$$_6H$_{12}O$_6) in 25.0 mL of $$water at 25 °C. What is the molality of glucose in the solution? (Molar mass of glucose = 180.2 g/mol, density of water = 1.00 g/mL)

$$\frac{4.35\ \text{g}}{180.2\ \text{g/mol}} \div 0.025\ \text{kg} = 0.97\ m$$

Q: What is the osmotic pressure ($$\Pi) of a 0.0020 M $$sucrose (C$$_{12}H$_{22}O$_{11}) $$solution at 20.0 °C? (R = 0.0821 L·atm/mol·K)

$$\Pi = (1)(0.0020\ \text{mol/L})(0.0821\ \text{L·atm/mol·K})(293\ \text{K}) = 0.048\ \text{atm}$$

Question 1

Which of the following best explains why mixing two gases, such as O$$_2$$ and Ar, is a spontaneous process?

Accepted Answer

The process increases the entropy of the system.

Question 2

Which intermolecular force is primarily responsible for the solubility of NaCl in water?

Accepted Answer

Ion-dipole interaction

Question 3

A solution is made by dissolving 13.5 g of glucose (C$$_6H$_{12}O$_6) in 0.100 kg of $$water. What is the mass percentage of glucose in the solution?

Accepted Answer

$$\frac{13.5}{13.5+100} 	imes 100 = 11.9\%$$

Question 4

Which of the following solvents will best dissolve wax, which is a complex mixture of compounds that mostly are CH$$_3$$–CH$$_2$$–CH$$_2$$–CH$$_2$$–CH$$_2$$—?

Accepted Answer

Hexane

Question 5

According to Henry’s Law, what happens to the solubility of a gas in a liquid if the partial pressure of the gas above the liquid is doubled?

Accepted Answer

The solubility is doubled.

Question 6

Which of the following statements about molality ($$m) $$and molarity ($$M) is $$correct?

Accepted Answer

Molality does not vary with temperature, but molarity does.

Question 7

A solution is made by dissolving 4.35 g of glucose (C$$_6H$_{12}O$_6) in 25.0 mL of $$water at 25 °C. What is the molality of glucose in the solution? (Molar mass of glucose = 180.2 g/mol, density of water = 1.00 g/mL)

Accepted Answer

$$\frac{4.35\ 	ext{g}}{180.2\ 	ext{g/mol}} \div 0.025\ 	ext{kg} = 0.97\ m$$

Question 8

Which aqueous solution will have the lowest freezing point?

Accepted Answer

0.15 m NaCl

Question 9

What is the osmotic pressure ($$\Pi) of a 0.0020 M $$sucrose (C$$_{12}H$_{22}O$_{11}) $$solution at 20.0 °C? (R = 0.0821 L·atm/mol·K)

Accepted Answer

$$\Pi = (1)(0.0020\ 	ext{mol/L})(0.0821\ 	ext{L·atm/mol·K})(293\ 	ext{K}) = 0.048\ 	ext{atm}$$

Question 10

Which of the following best describes the Tyndall effect?

Accepted Answer

The scattering of light by colloidal particles.

Question 11

A solution contains 36% HCl by mass. What is the mole fraction of HCl in the solution? (Molar mass HCl = 36.5 g/mol, Molar mass H$$_2O = 18.0 g/$$mol)

Accepted Answer

$$\frac{0.99}{0.99+3.6} = 0.22$$

Question 12

Which of the following actions will raise the osmotic pressure of a solution?

Accepted Answer

Increasing the solute concentration

Question 13

Which statement about colligative properties is correct?

Accepted Answer

They depend only on the number of solute particles, not their identity.

Question 14

Which of the following best describes a supersaturated solution?

Accepted Answer

A solution that contains more solute than is normally possible at that temperature.

Question 15

Which of the following is a real-life consequence of osmotic pressure in biological systems?

Accepted Answer

Red blood cells will burst in a hypotonic solution due to hemolysis.

Question 16

Which equation represents Raoult’s Law for the vapor pressure of a solution?

Accepted Answer

$$P_{	ext{solution}} = X_{	ext{solvent}} P$$^{\circ}$$_{	ext{solvent}}$$

Question 17

A solution is made by dissolving 0.250 g of a nonvolatile nonelectrolyte in 40.0 g of CCl$$_4. $$The boiling point elevation is 0.357 °C. If $$K_b$$ for CCl$$_4 is 5.02$$ °C/m, what is the molar mass of the solute?

Accepted Answer

$$\frac{0.250\ 	ext{g}}{0.00284\ 	ext{mol}} = 88.0\ 	ext{g/mol}$$

Question 18

Which of the following best describes the effect of adding a nonvolatile solute to a solvent?

Accepted Answer

The vapor pressure of the solvent decreases.

Properties of Solutions: Structure, Formation, and Colligative Effects

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