Q: Which of the following is the correct formula for calculating molality ($m$)?

$m = \frac{\text{moles of solute}}{\text{kg of solvent}}$

Q: Which of the following is the correct formula for mole fraction ($X_A$) of component A in a solution?

$X_A = \frac{\text{moles of A}}{\text{total moles in solution}}$

Q: Which of the following best describes a saturated solution?

A solution in which no more solute can dissolve at a given temperature.

Q: Which of the following is the correct formula for percent by mass?

$\%\text{ by mass} = \frac{\text{mass of solute}}{\text{mass of solution}} \times 100$

Q: Which of the following is a correct statement about intermolecular forces and solubility?

Polar solutes dissolve best in polar solvents due to dipole interactions.

Q: A soil sample contains $7.78 \times 10^{18}$ ions of Pb$^{2+}$ in 3.57 g of soil. The molar mass of Pb is 207.2 g/mol. Does this sample exceed the EPA limit of 400 ppm by mass for playgrounds?

Yes, the sample exceeds the EPA limit.

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

Solubility of gases decreases with increasing temperature.

Question 1

Which of the following best describes the process that must occur for NaCl to dissolve in water?

Accepted Answer

Both solute-solute and solvent-solvent interactions must be overcome, and new solute-solvent interactions form.

Question 2

Which of the following is the correct formula for calculating molality ($m$)?

Accepted Answer

$m = \frac{	ext{moles of solute}}{	ext{kg of solvent}}$

Question 3

A solution is prepared by dissolving 2.00 mol of NaCl in enough water to make 1.00 L of solution. What is the molarity ($M$) of the solution?

Accepted Answer

$M = 2.00\ 	ext{mol/L}$

Question 4

Which of the following intermolecular forces is strongest in a solution of NaCl in water?

Accepted Answer

Ion-dipole interactions

Question 5

Which of the following statements about solubility is correct?

Accepted Answer

Solubility is the amount of solute that dissolves in a given amount of solvent at a specific temperature.

Question 6

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules are nonpolar and cannot form hydrogen bonds with water.

Question 7

A 0.200 M solution of NaCl has a density of 1.15 g/mL. What is the molality ($m$) of the solution? (Assume 1 L of solution.)

Accepted Answer

$m = 0.174\ 	ext{mol/kg}$

Question 8

Which of the following is the correct formula for mole fraction ($X_A$) of component A in a solution?

Accepted Answer

$X_A = \frac{	ext{moles of A}}{	ext{total moles in solution}}$

Question 9

Which of the following best describes an exothermic process in solution formation?

Accepted Answer

$\Delta H_{	ext{soln}} < 0$

Question 10

Which of the following is a real-world example of a gas dissolved in a liquid?

Accepted Answer

Club soda (CO$_2$ in water)

Question 11

Which of the following concentration units is temperature-independent?

Accepted Answer

Molality ($m$)

Question 12

A solution contains 0.5 mol of ethanol and 1.5 mol of water. What is the mole fraction of ethanol?

Accepted Answer

$X_{	ext{ethanol}} = 0.25$

Question 13

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which no more solute can dissolve at a given temperature.

Question 14

Which of the following is the correct formula for percent by mass?

Accepted Answer

$\%	ext{ by mass} = \frac{	ext{mass of solute}}{	ext{mass of solution}} 	imes 100$

Question 15

Which of the following would increase the solubility of a solid solute in water?

Accepted Answer

Increasing the temperature

Question 16

Which of the following is a correct statement about intermolecular forces and solubility?

Accepted Answer

Polar solutes dissolve best in polar solvents due to dipole interactions.

Question 17

A soil sample contains $7.78 	imes 10^{18}$ ions of Pb$^{2+}$ in 3.57 g of soil. The molar mass of Pb is 207.2 g/mol. Does this sample exceed the EPA limit of 400 ppm by mass for playgrounds?

Accepted Answer

Yes, the sample exceeds the EPA limit.

Question 18

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

Accepted Answer

Solubility of gases decreases with increasing temperature.

Question 19

Which of the following is the strongest intermolecular force present in a solution of H$_2$O?

Accepted Answer

Hydrogen bonding

Question 20

Which of the following is a correct example of a solution where the solute and solvent are both solids?

Accepted Answer

Brass (Cu and Zn)

General Chemistry Study Notes: Solutions, Solubility, and Concentration (Chem 166, Lecture 1)

Study Guide - Practice Questions

Study Guide - Flashcards