# How would you write the Henderson-Hasselbalch equation for a solution of propanoic acid (CH_3CH2CO2H, pKa = 4.874 ) using HA, A–, and the given pKa value in the expression?

Feb 4, 2017

$p H = p {K}_{a} + {\log}_{10} \left(\frac{\left[{A}^{-}\right]}{\left[H A\right]}\right)$ is the general equation.........
$p H = 4.874 + {\log}_{10} \left(\frac{\left[{A}^{-}\right]}{\left[H A\right]}\right)$
$p H = p {K}_{a} = 4.874$. Why so?