The of formic acid,

CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases

Problem

The

pK_a

of formic acid,

\mathrm{HCOOH}

, is 3.75 at

25\,^{\circ}\text{C}

. What is the equilibrium concentration of formate ion,

\mathrm{HCOO^-}

, in a

0.25\,\text{M}

sample of formic acid solution prepared at this temperature? (a)

1.3 \times 10^{-2}\,\text{M}

(b)

6.7 \times 10^{-3}\,\text{M}

(c)

2.5 \times 10^{-1}\,\text{M}

(d)

1.8 \times 10^{-4}\,\text{M}