Question

Calculate the salt to acid ratio ([Aˉ]/[HA]) of a solution of an amino acid at pH 2 and 

pKa of 8.95

Answer 1

$pH=pKa+log\frac{[A^-]}{[HA]}$

$2=8.95+log\frac{[A^-}{[HA]}$

$-6.95=log\frac{[A^-]}{[HA]}$

$log\frac{[A_]}{[HA]}=10^{-6.95}$