$$5 \times 10$$^{-9}$$\ \mathrm{M}$$

$$K_a \times K_b = 1.0 \times 10$$^{-14}$$

Question 1

Which of the following best describes an Arrhenius acid?

Accepted Answer

A substance that increases the concentration of hydrogen ions when dissolved in water.

Question 2

Which of the following is an example of an amphiprotic species?

Accepted Answer

All of the above

Question 3

What is the conjugate base of $$\mathrm{$$HSO_4$$^-}$$?

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 4

A solution has $$[\mathrm{H^+}] = 4 	imes 10$$^{-9}$$\ \mathrm{M}. Is $$the solution acidic, basic, or neutral?

Accepted Answer

Basic

Question 5

Calculate the pH of a solution with $$[\mathrm{H^+}] = 3.8 	imes 10$$^{-4}$$\ \mathrm{M}.$$

Accepted Answer

3.42

Question 6

Which of the following statements about strong acids is correct?

Accepted Answer

Strong acids have weak conjugate bases.

Question 7

What is the $$[\mathrm{OH^-}] in a $$solution where $$[\mathrm{H^+}] = 2 	imes 10$$^{-6}$$\ \mathrm{M} at 25$$°C?

Accepted Answer

$$5 	imes 10$$^{-9}$$\ \mathrm{M}$$

Question 8

Which of the following is a Lewis acid but not a Brønsted–Lowry acid?

Accepted Answer

$$\mathrm{BF_3$}$$

Question 9

A 0.020 M solution of niacin has a pH of 3.26. What is the percent ionization of niacin in this solution?

Accepted Answer

2.7%

Question 10

Which of the following salts will form the more acidic 0.010 M solution?

Accepted Answer

$$\mathrm{Fe(NO_3$)_3}$$

Question 11

Which of the following statements about the autoionization of water is correct?

Accepted Answer

It produces equal concentrations of $$\mathrm{H_3O^+}$$ and $$\mathrm{OH^-} in $$pure water.

Question 12

Which of the following will produce the highest pH as a 0.05 M solution?

Accepted Answer

Methylamine

Question 13

What is the relationship between $$K_a$$ and $$K_b$$ for a conjugate acid–base pair at 25°C?

Accepted Answer

$$K_a 	imes K_b = 1.0 	imes 10$$^{-14}$$

Question 14

Which factor increases the strength of a binary acid HX?

Accepted Answer

Increasing the stability of the conjugate base X-

Question 15

Which of the following is true for a polyprotic acid?

Accepted Answer

The $$K_a$$ for the first dissociation is always larger than for the second.

Question 16

A solution of $$\mathrm{NH_3$} in $$water has a pH of 11.17. What is the molarity of the solution?

Accepted Answer

0.12 M

Question 17

Which of the following is a correct statement about the pH and pOH scales at 25°C?

Accepted Answer

pH + pOH = 14

Question 18

Which of the following is a correct definition of a Lewis base?

Accepted Answer

A substance that donates a pair of electrons.

Question 19

Which of the following anions will have the largest base-dissociation constant ($$K_b$$)?

Accepted Answer

$$\mathrm{PO_4$^{3-}}$$

Question 20

Which of the following factors will increase the acidity of an oxyacid?

Accepted Answer

Increasing the electronegativity of the central atom

Acid–Base Equilibria: Concepts, Calculations, and Applications

Study Guide - Practice Questions