Consider the buffer system of hydrofluoric acid, HF, and

Chapter 14, Problem 61QP

(choose chapter or problem)

Consider the buffer system of hydrofluoric acid, HF, and its salt, NaF.

                     \(\mathrm{HF}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftarrows \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{F}^{-}(a q)\)

a. The purpose of the buffer system is to:

1. maintain [HF]

2. maintain \(\left[\mathrm{F}^{-}\right]\)

3. maintain pH

b. The salt of the weak acid is needed to:

1. provide the conjugate base

2. neutralize added \(\mathrm{H}_{3} \mathrm{O}^{+}\)

3. provide the conjugate acid

c. The addition of \(\mathrm{OH}^{-}\) is neutralized by:

1. the salt

2. \(\mathrm{H}_{2} \mathrm{O}\)

3. \(\mathrm{H}_{3} \mathrm{O}^{+}\)

d. When \(\mathrm{H}_{3} \mathrm{O}^{+}\) is added, the equilibrium shifts in the direction of the.

1. reactants

2. products

3. does not change