Q: A solution is prepared by dissolving 10.0 g of NaCl (molar mass = 58.44 g/mol) in enough water to make 500.0 mL of solution. What is the molarity ($$M) of $$the solution?

$$M = \frac{10.0\ \text{g}}{58.44\ \text{g/mol}} \div 0.500\ \text{L} = 0.342\ M$$

Q: A 1.00 m solution of Na2SO4 (sodium sulfate) is prepared. What is the total concentration of dissolved particles (in molality) in the solution, considering complete dissociation?

$$1.00\ m \times 3 = 3.00\ m ($$since Na2SO4 dissociates into 2 Na^+ and 1 $$SO_4$$^{2-})

Q: A sample of water is heated from $$25^\circ\text{C} to$$ $$100^\circ\text{C}$$ and then boiled to steam at $$100^\circ\text{C}. $$Which of the following statements is true regarding the energy changes involved?

Heating from $$25^\circ\text{C} to$$ $$100^\circ\text{C}$$ increases kinetic energy; boiling at $$100^\circ\text{C}$$ increases potential energy.

Q: Which of the following is the correct balanced equation for the reaction of hydrochloric acid with sodium carbonate?

$$2\ \text{HCl} (aq) + \text{Na}_2\text{CO}_3 (aq) \rightarrow 2\ \text{NaCl} (aq) + \text{H}_2\text{O} (l) + \text{CO}_2 (g)$$

Question 1

Which of the following statements best explains why table salt (NaCl) dissolves readily in water but not in hexane (C6H14)?

Accepted Answer

NaCl is ionic and water is polar, so ion-dipole interactions stabilize the ions in solution.

Question 2

A solution is prepared by dissolving 10.0 g of NaCl (molar mass = 58.44 g/mol) in enough water to make 500.0 mL of solution. What is the molarity ($$M) of $$the solution?

Accepted Answer

$$M = \frac{10.0\ 	ext{g}}{58.44\ 	ext{g/mol}} \div 0.500\ 	ext{L} = 0.342\ M$$

Question 3

Which of the following changes will increase the solubility of a gas in a liquid, according to Henry’s Law?

Accepted Answer

Increasing the pressure of the gas above the liquid.

Question 4

A 1.00 m solution of Na2SO4 (sodium sulfate) is prepared. What is the total concentration of dissolved particles (in molality) in the solution, considering complete dissociation?

Accepted Answer

$$1.00\ m 	imes 3 = 3.00\ m ($$since Na2SO4 dissociates into 2 Na^+ and 1 $$SO_4$$^{2-})

Question 5

Which of the following best describes the effect of a catalyst on a chemical reaction at equilibrium?

Accepted Answer

It decreases the activation energy, allowing equilibrium to be reached faster, but does not change the equilibrium constant ($$K_{eq}).$$

Question 6

Which of the following compounds exhibits hydrogen bonding as its strongest intermolecular force?

Accepted Answer

CH3OH (methanol)

Question 7

A sample of water is heated from $$25^\circ	ext{C} to$$ $$100^\circ	ext{C}$$ and then boiled to steam at $$100^\circ	ext{C}. $$Which of the following statements is true regarding the energy changes involved?

Accepted Answer

Heating from $$25^\circ	ext{C} to$$ $$100^\circ	ext{C}$$ increases kinetic energy; boiling at $$100^\circ	ext{C}$$ increases potential energy.

Question 8

Which of the following best describes a buffer solution?

Accepted Answer

A solution that resists changes in pH when small amounts of acid or base are added.

Question 9

Which of the following is the correct balanced equation for the reaction of hydrochloric acid with sodium carbonate?

Accepted Answer

$$2\ 	ext{HCl} (aq) + 	ext{Na}_2	ext{CO}_3 (aq) ightarrow 2\ 	ext{NaCl} (aq) + 	ext{H}_2	ext{O} (l) + 	ext{CO}_2 (g)$$

Question 10

A reaction has an equilibrium constant $$K_{eq} = 1.2 	imes 10^3$ at 25$$^\circ	ext{C}$$. Which statement is true about the reaction at equilibrium?

Accepted Answer

Products are favored over reactants at equilibrium.

Question 11

Which of the following changes will shift the equilibrium of the reaction $$	ext{N}_2 (g) + 3\ 	ext{H}_2 (g) ightleftharpoons 2\ 	ext{NH}_3 (g) to $$the right, according to Le Chatelier’s principle?

Accepted Answer

Increasing the pressure by decreasing the volume.

Question 12

Which of the following is the correct oxidation number for sulfur in $$	ext{H}_2	ext{SO}_4$$?

Accepted Answer

+6

Question 13

A 0.10 M solution of a weak acid, HA, has a pH of 3.0. What is the concentration of $$[	ext{H}_3	ext{O}^+] in $$the solution?

Accepted Answer

$$[	ext{H}_3	ext{O}^+] = 10$$^{-3.0}$$ = 1.0 	imes 10$$^{-3}$$\ 	ext{M}$$

Question 14

Which of the following best describes the process of corrosion of iron and the role of a sacrificial anode?

Accepted Answer

The sacrificial anode is more easily oxidized than iron, so it corrodes instead of the iron.

Question 15

Which of the following is a property of a crystalline solid but not an amorphous solid?

Accepted Answer

A regular, repeating arrangement of particles.

Question 16

A solution is prepared by mixing 50.0 mL of 6.0 M HCl with enough water to make 300.0 mL of solution. What is the final concentration of HCl?

Accepted Answer

$$M_2$$ = \frac{$$M_1$$ $$V_1$$}{$$V_2$$} = \frac{6.0\ 	ext{M} 	imes 50.0\ 	ext{mL}}{300.0\ 	ext{mL}} = 1.0\ 	ext{M}$$

Question 17

Which of the following statements about the boiling point elevation of a solution is correct?

Accepted Answer

The boiling point elevation is directly proportional to the molality and the number of particles produced by solute dissociation.

Question 18

Which of the following best describes the effect of increasing temperature on the rate of a chemical reaction?

Accepted Answer

It increases the rate by increasing the number of effective collisions between reactant molecules.

Question 19

Which of the following is the correct net ionic equation for the reaction between hydrochloric acid and sodium hydroxide?

Accepted Answer

$$	ext{H}^+ (aq) + 	ext{OH}^- (aq) ightarrow 	ext{H}_2	ext{O} (l)$$

Question 20

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

Accepted Answer

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

Final Exam Study Guide: Solutions, Intermolecular Forces, Equilibrium, Acids & Bases, and Redox Chemistry

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