Acid-Base Equilibrium

Which is the weakest acid from the choices given?

• HF

• HNO₂

• CH₃COOH

• HClO

A substance that ionizes completely in solution is

• an insulator.
• a strong electrolyte. 
• a weak acid.
• a non-electrolyte.

Which of the following is a conjugate acid/base pair?

• HCl/OCl^-
• H₂SO₄/SO₄^2-
• NH₄⁺/NH₃
• H₃O⁺/OH^-

The pH of a solution at 25^ₒC in which [OH-] = 3.9 x 10^-5M is:

• 4.41
• 3.90
• 9.59
• 4.80

Calculate the pH of a 0.47M NH₃ (K_b = 1.8 x 10^-5) solution.

• 2.54
• 8.93
• 5.07
• 11.46

Calculate the [H⁺] in a solution that has a pH of 2.73.

• 5.4 x 10^-12 M
• 1.9 x 10^-3 M
• 2.7 M
• 11.3 M

The pH at the equivalence point of the titration of a strong acid with a strong base is:

• 3.9
• 4.5
• 7.0
• 8.2

Which of the following is not a strong acid?

• nitric, HNO₃

• sulfuric, H₂SO₄

• perchloric, HClO₄

• hydrofluoric, HF

What is the pH of a 0.25 M solution of LiOH?

• 0.25
• 13.4
• 0.60
• 12.3

What is the pH of a 0.15 M solution of HClO₄?

• 0.82
• 13.18
• 0.15
• 1