A buffer has a pH of 4.20 and was made by mixing 50 of a weak acid with a of 3.98 and…

CHEMISTRY · Subjective · A Level · Chemistry · Acids and bases · Acids and bases

Problem

A buffer has a pH of 4.20 and was made by mixing 50

\text{cm}^3

of a weak acid with a

\text{p}K_a

of 3.98 and a concentration of

0.200 \text{ mol dm}^{-3}

with 50

\text{cm}^3

of its salt. Calculate the concentration of salt solution used.