Q: Which of the following is the correct formula for calculating molarity ($$C) of a $$solution?

$$C = \frac{\text{Amount of solute (in moles)}}{\text{Volume of solution (in liters)}}$$

Q: Which of the following statements about the enthalpy of solution ($$\Delta H_{\text{soln}}) is $$correct?

$$\Delta H_{\text{soln}}$$ can be positive, negative, or zero depending on the intermolecular forces involved.

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

$$C = k \times P_{\text{gas}}$$

Question 1

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture with uniform composition throughout.

Question 2

Which of the following is the correct formula for calculating molarity ($$C) of a $$solution?

Accepted Answer

$$C = \frac{	ext{Amount of solute (in moles)}}{	ext{Volume of solution (in liters)}}$$

Question 3

A solution is prepared by dissolving 10.0 g of NaCl in enough water to make 500 mL of solution. What is the molarity of the solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$0.171\ 	ext{M}$$

Question 4

Which of the following statements about the enthalpy of solution ($$\Delta H_{	ext{soln}}) is $$correct?

Accepted Answer

$$\Delta H_{	ext{soln}}$$ can be positive, negative, or zero depending on the intermolecular forces involved.

Question 5

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

Accepted Answer

$$C = k 	imes P_{	ext{gas}}$$

Question 6

A 0.0100 m NaCl(aq) solution has an observed freezing point depression of $$-0.0361\ ^\circ	ext{C}. $$The expected value is $$-0.0186\ ^\circ	ext{C}. $$What is the van’t Hoff factor ($$i) $$for this solution?

Accepted Answer

$$i = 1.98$$

Question 7

Which of the following best explains why the vapor pressure of a solvent decreases when a nonvolatile solute is added?

Accepted Answer

The solute particles occupy surface area, reducing the number of solvent molecules able to escape into the vapor phase.

Question 8

Calculate the osmotic pressure ($$\pi) at$$ $$25\ ^\circ	ext{C}$$ for a $$0.0010\ 	ext{M}$$ sucrose solution. ($$R = 0.08206\ 	ext{L atm mol}^{-1}	ext{K}^{-1}$$, $$T = 298\ 	ext{K})$$

Accepted Answer

$$0.024\ 	ext{atm}$$

Question 9

Which of the following is a colloidal mixture?

Accepted Answer

Milk

Question 10

Which of the following equations correctly describes freezing-point depression for a nonelectrolyte solution?

Accepted Answer

$$\Delta T_f = K_f \cdot m$$

Question 11

A red blood cell is placed in a solution and it shrivels. What can you conclude about the solution?

Accepted Answer

The solution is hypertonic relative to the cell.

Question 12

Which of the following best describes the Tyndall effect?

Accepted Answer

The scattering of light by particles in a colloid.

Question 13

Which of the following is the correct expression for Raoult’s Law for the vapor pressure of a solvent in an ideal solution?

Accepted Answer

$$P_A = \chi_A P_A^\circ$$

Question 14

A solution contains 1.50 g of $$C_{12}H$$_{22}$$O_{11} ($$sucrose) in 125 mL of water at $$25\ ^\circ	ext{C}. $$What is the osmotic pressure? ($$R = 0.08206\ 	ext{L atm mol}^{-1}	ext{K}^{-1}$$, $$T = 298\ 	ext{K}$, molar mass of sucrose = 342 g/mol)

Accepted Answer

$$0.13\ 	ext{atm}$$

Question 15

Which of the following is true about the effect of temperature on the solubility of gases in water?

Accepted Answer

Solubility decreases as temperature increases.

Question 16

Which of the following best describes an ideal solution?

Accepted Answer

A solution in which the intermolecular forces between all combinations of components are similar and $$\Delta H_{	ext{soln}} = 0.$$

Question 17

Which of the following is a correct statement about colligative properties?

Accepted Answer

They depend only on the concentration of solute particles.

Question 18

A solution is made by mixing 50.0 g of ethanol ($$C_2H_5OH$$, molar mass = 46.07 g/mol) with 100.0 g of water (molar mass = 18.02 g/mol). What is the mole fraction of ethanol in the solution?

Accepted Answer

$$0.176$$

Question 19

Which of the following is a real-life application of osmotic pressure?

Accepted Answer

Preserving food by salting or sugaring.

Solutions and Their Physical Properties: General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard