Question

Hydroxyl ion concentration of pure water is 8.4*10 power-8 calculate ionic product at this temperature

Answer 1

In pure water,
$[H^+]=[OH^-]=8.4\times 10^{-8}\\ K_w=[H^+][OH^-]\\ =(8.4\times 10^{-8})^2\\ =7.056\times 10^{-15}$