Acid Base Equilibria #3

Which of the following is not a strong acid?

• nitric
• sulfuric
• perchloric
• hydrofluoric

The dissociation constants for sulfurous acid (H₂SO₃) are Ka₁= 1.7 x 10^-2 and Ka₂= 6.4 x 10^-8. What is the pH of a 0.163 M H₂SO₃ solution?

• 4.52

• 7.26

• 1.45

• 1.35

• 1.83

What is the conjugate acid of NH₃?

• NH₄⁺

• NH₂^-

• NH₄OH

• NH₄

Answer explanation

What does the particle become after it takes the H⁺?

What is the conjugate base of HSO₄^-

• H₂SO₄

• SO₄^2-

• H₂SO₄⁺

• HSO₄^2-

Answer explanation

what happens does it become after it loses its H⁺

Calculate the pH of a 0.500 M NH₃ solution. The K_b of ammonia is 1.77E-5.

• 12.58

• 2.98

• 11.47

• 10.69

The acid dissociation constants for phosphoric acid (H₃PO₄) are:

Ka₁= 7.5E-3

Ka₂= 6.2E-8

Ka₃= 4.2E-13

What is the concentration of phosphate (PO₄^3-) in a 2.5M phosphoric acid solution?

• 2.0E-19

• 9.1E-5

• 0.13

• 2.5E-5

• 8.2E-9

The Ka for gallic acid is 4.57E-3. What is the Kb for gallate ion?

• 4.57E-3

• 5.43E-5

• 2.19E-12

• 7.81E-6

The Ka for HF is 7.0E-4. What is the Kb for F^-?

• 1.4E-11

• 2.0E-8

• 7.0E-18

• 7.0E-4

• 1.4E3

Determine the pH of 0.15 M KF. The Ka of HF is 7.0E-4.

• 2.30

• 5.12

• 7.83

• 8.17

Answer explanation

Write the equilibrium when F^- is added to water.

Calculate the pH of 0.726 M anilinium hydrochloride (C₆H₅NH₃Cl). The Kb of aniline (C₆H₅NH₂) is 3.83E-4.

(Hint: pretend that you have ammonium chloride and you are given the Kb of ammonia)

• 5.36

• 8.88

• 4.55

• 3.33