Question

What is the pH of a 0.222 M acetic acid solution?

Answer 1

pH=2.7

Further explanation

Acetic acid = weak acid

$\tt [H^+]=\sqrt{Ka.M}$

Ka = acid ionization constant

M = molarity

Ka for Acetic acid(CH₃COOH) : 1.8 x 10⁻⁵

$\tt [H^+]=\sqrt{1.8\times 10^{-5}\times 0.222}\\\\=0.001998=1.998\times 10^{-3}$

$\tt pH=3-log~1.998=2.7$