Acids, Bases, & Salts (MC)

Question 1

When 200. mL of 2.0 M NaOH(aq) is added to 500. mL of 1.0 M HCl(aq), the pH of the resulting mixture is closest to

a. 1.0
b. 3.0
c. 7.0
d. 13.0

Answer 1

A

Question 2

A solution containing HCl and the weak acid HClO₂ has a pH of 2.4. Enough KOH(aq) is added to the solution to increase the pH to 10.5. The amount of which of the following species increases as the KOH(aq) is added?

a. Cl^-(aq)
b. H⁺(aq)
c. ClO₂^-(aq)
d. HClO₂(aq)

Answer 2

C

Question 3

2H₂O(l) ⇔ H₃O⁺(aq) + OH^-(aq)

The autoionization of water is represented by the equation above. Values of pK_w at various temperatures are listed below.

Temperature (ºC) – pK_w

0 – 14.9

10 – 14.5

20 – 14.2

30 – 13.8

40 – 13.5

Based on the information above, which of the following statements is true?

a. The dissociation of water is an exothermic process.
b. The pH of pure water is 7.00 at any temperature.
c. As the temperature increases, the pH of pure water increases.
d. As the temperature increases, the pH of pure water decreases.

Answer 3

D