$CH_3COOH = (0.2 + 1) = 1.2 \,mol \,litre^{-1}$
[ક્ષાર] = $(1 - 0.2) = 0.8\, mol\, L^{-1}$
હેન્ડરસનનું સમીકરણ લાગુ પાડતા,
$pH = \log \frac{{[Salt]}}{{[Acid]}} - \log \,{K_a} = \log \frac{{0.8}}{{1.2}} - \log \,1.8 \times {10^{ - 5}} $
$= \log 2 - \log 3 - \log 1.8 \times {10^{ - 5}} = 4.56$