Q: A solution is prepared by dissolving 10 g of NaCl in 90 g of water. What is the mass percent ($$\%\,\mathrm{m/m}) of $$NaCl in the solution?

$$\frac{10}{100} \times 100 = 10\%$$

Q: A 0.5 M solution of glucose is diluted to a final volume of 1.0 L. If the initial volume was 0.2 L, what is the final concentration?

$$0.5\,\mathrm{M} \times \frac{0.2\,\mathrm{L}}{1.0\,\mathrm{L}} = 0.1\,\mathrm{M}$$

Question 1

Which of the following best describes the difference between a solvent and a solute in a solution?

Accepted Answer

The solvent is the substance present in the largest amount, and the solute is present in a smaller amount.

Question 2

Water is often referred to as the 'universal solvent.' Which property of water is primarily responsible for its ability to dissolve many substances?

Accepted Answer

Water is polar, allowing it to dissolve ionic and polar solutes.

Question 3

Which of the following solutes would be most soluble in water?

Accepted Answer

Sodium chloride ($$\mathrm{NaCl}$$), an ionic compound

Question 4

Which statement correctly describes the effect of temperature on solubility?

Accepted Answer

Increasing temperature increases the solubility of solids in water but decreases the solubility of gases in water.

Question 5

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

Accepted Answer

The solubility of the gas increases.

Question 6

A solution is prepared by dissolving 10 g of NaCl in 90 g of water. What is the mass percent ($$\%\,\mathrm{m/m}) of $$NaCl in the solution?

Accepted Answer

$$\frac{10}{100} 	imes 100 = 10\%$$

Question 7

A 0.5 M solution of glucose is diluted to a final volume of 1.0 L. If the initial volume was 0.2 L, what is the final concentration?

Accepted Answer

$$0.5\,\mathrm{M} 	imes \frac{0.2\,\mathrm{L}}{1.0\,\mathrm{L}} = 0.1\,\mathrm{M}$$

Question 8

Which of the following best describes a strong electrolyte?

Accepted Answer

A substance that completely dissociates in water, producing ions and conducting electricity strongly.

Question 9

Which colligative property explains why adding salt to water causes the water to boil at a higher temperature?

Accepted Answer

Boiling point elevation

Question 10

A patient receives an intravenous solution that is hypotonic relative to their blood plasma. What is the likely outcome for their red blood cells?

Accepted Answer

Red blood cells will swell and possibly burst due to water entering the cells.

Question 11

Which of the following statements about activation energy is correct?

Accepted Answer

Activation energy is the minimum energy required for a reaction to occur.

Question 12

Which factor does NOT affect the rate of a chemical reaction?

Accepted Answer

Amount of product formed

Question 13

Which statement best describes the role of a catalyst in a chemical reaction?

Accepted Answer

A catalyst lowers the activation energy, increasing the reaction rate.

Question 14

Which of the following is a reversible chemical reaction?

Accepted Answer

$$\mathrm{aA + bB \rightleftharpoons cC + dD}$$

Question 15

Write the equilibrium expression for the reaction $$\mathrm{aA + bB \rightleftharpoons cC + dD}.$$

Accepted Answer

$$K_c = \frac{[C]^c [D]^d}{[A]^a [B]^b}$$

Question 16

If the equilibrium constant $$K_c$$ for a reaction is much greater than 1, what does this indicate about the reaction at equilibrium?

Accepted Answer

The reaction favors the formation of products.

Question 17

According to Le Châtelier’s principle, what happens to the equilibrium position if more reactant is added to a system at equilibrium?

Accepted Answer

The equilibrium shifts to produce more products.

Question 18

Which of the following is an Arrhenius acid?

Accepted Answer

$$\mathrm{HCl}$$

Question 19

What is the equation for the reaction of HCl with water?

Accepted Answer

$$\mathrm{HCl + H_2O \rightarrow Cl^- + H_3O^+}$$

Question 20

Which pair represents a conjugate acid-base pair?

Accepted Answer

$$\mathrm{H_2O}$$ and $$\mathrm{OH^-}$$

Question 21

Which of the following acids is considered strong?

Accepted Answer

$$\mathrm{$$HNO_3$$} ($$nitric acid)

Question 22

What is the equilibrium expression for the dissociation of a weak acid $$\mathrm{HA} in $$water?

Accepted Answer

$$K_a = \frac{[H^+][A^-]}{[HA]}$$

Question 23

What is the value of $$K_w$$ for the dissociation of water at 25°C?

Accepted Answer

$$1.0 	imes 10$$^{-14}$$

Question 24

If the $$[H_3O^+] in a $$solution is $$1.0 	imes 10$$^{-3}$$\,\mathrm{M}$$, what is the pH of the solution?

Accepted Answer

$$pH = -\log(1.0 	imes 10$$^{-3}$$) = 3$$

Question 25

Which of the following best describes a buffer?

Accepted Answer

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

Question 26

Which of the following is a biologically relevant buffer system in human blood?

Accepted Answer

Bicarbonate buffer

Guided Study for CHEM 14: Solutions, Equilibrium, and Acids/Bases

Guida di studio - Domande di pratica

Study guide - Flashcard