Question

Determine the concentration of hydronium ions in a 0.18 mol/L solution of perchloric acid.

Answer 1

$HClO_4 (aq) \space + H_2O (l) \to \space H_3O^+ (aq) \space ClO_4^- (aq)$

$pH = -log[H^+]$

$[H_3O^+] = [H^+] = [ClO_4^-] = 0.18 mol/L$