Q: Which equation correctly relates the vapor pressure lowering to the mole fraction of solute in an ideal solution?

$$\\Delta P = X_{solute} \\cdot P^0$_{solvent}$$

Q: Which of the following is the correct formula for calculating the boiling point elevation of a solution?

$$\\Delta T_b = K_b \\cdot m \\cdot i$$

Q: A solution is prepared by dissolving 5 g of a nonvolatile solute in 100 g of water. The vapor pressure of pure water at 25$$^\circC is 23.8 $$mmHg. If the mole fraction of water in the solution is 0.98, what is the vapor pressure of the solution?

$$0.98 \\ \times \\ 23.8 \\ \text{mmHg} = 23.3 \\ \text{mmHg}$$

Question 1

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which the maximum amount of solute has been dissolved at a given temperature.

Question 2

Which of the following statements about solubility is correct?

Accepted Answer

Solubility of gases in water decreases as temperature increases.

Question 3

A solution is prepared by dissolving 10 g of NaCl in 100 g of water. Which component is the solvent?

Accepted Answer

Water

Question 4

Which equation correctly relates the vapor pressure lowering to the mole fraction of solute in an ideal solution?

Accepted Answer

$$\Delta P = X_{solute} \cdot P^0$_{solvent}$$

Question 5

Which of the following best explains why salt is spread on icy roads in winter?

Accepted Answer

Salt decreases the freezing point of water, causing ice to melt.

Question 6

A cell is placed in a hypotonic solution. What will happen to the cell?

Accepted Answer

The cell will swell as water enters the cell.

Question 7

Which of the following is a colligative property?

Accepted Answer

Boiling point elevation

Question 8

A solution is made by dissolving 2 moles of glucose ($$C_6H_{12}O_6$) in 1 kg of water. What is the molality of the solution?

Accepted Answer

$$2 \ 	ext{mol/kg}$$

Question 9

Which of the following best describes why ionic compounds have a greater effect on colligative properties than covalent compounds?

Accepted Answer

Ionic compounds dissociate into more particles, increasing the effect.

Question 10

Which of the following is the correct formula for calculating the boiling point elevation of a solution?

Accepted Answer

$$\Delta T_b = K_b \cdot m \cdot i$$

Question 11

A solution contains 0.5 mol of NaCl and 0.5 mol of KBr in 1 kg of water. Assuming complete dissociation, what is the total number of moles of particles in solution?

Accepted Answer

2 mol Na$$^+$$, 2 mol Cl$$^-$$ and Br$$^-$$, total 2 mol NaCl and KBr, but 2 mol Na$$^+$$, 1 mol Cl$$^-$$, 1 mol Br$$^-$$, total 2 mol cations and 2 mol anions, so 2 mol Na$$^+ + 1 $$mol Cl$$^- + 1 $$mol Br$$^- = 4 $$mol particles

Question 12

Which of the following best explains why the effective concentration of solute particles is less than predicted for ionic compounds in concentrated solutions?

Accepted Answer

Ion pairing reduces the number of free particles.

Question 13

Which of the following is NOT a colligative property?

Accepted Answer

Molar mass

Question 14

A solution is prepared by dissolving 5 g of a nonvolatile solute in 100 g of water. The vapor pressure of pure water at 25$$^\circC is 23.8 $$mmHg. If the mole fraction of water in the solution is 0.98, what is the vapor pressure of the solution?

Accepted Answer

$$0.98 \ 	imes \ 23.8 \ 	ext{mmHg} = 23.3 \ 	ext{mmHg}$$

Question 15

Which of the following best describes a hypertonic solution relative to a cell?

Accepted Answer

The solution has a higher solute concentration than the cell.

Question 16

Which of the following is the correct formula for osmotic pressure ($$\Pi) of a $$solution?

Accepted Answer

$$\Pi = iMRT$$

Question 17

Which of the following best explains why soap is effective at cleaning oily substances?

Accepted Answer

Soap molecules have both polar and nonpolar regions, allowing them to emulsify oils in water.

Question 18

Which of the following is the best definition of a colloid?

Accepted Answer

A mixture with particles large enough to scatter light but not settle out.

Question 19

A solution is made by dissolving 0.1 mol of NaCl in 1 kg of water. If the van't Hoff factor ($$i) $$for NaCl is 1.8 due to ion pairing, what is the effective molality of particles in solution?

Accepted Answer

$$0.18 \ 	ext{mol/kg}$$

Question 20

Which of the following best describes the process of dialysis as used in medical treatments?

Accepted Answer

It uses a semipermeable membrane to separate large colloidal particles from small ions and molecules.

Properties of Solutions and Solution Chemistry (Chapter 13 Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard