Question

If a solution's hydronium ion concentration is 1.0E-10 what is it's hydroxide ion concentration?Express your answer in Scientific notation using the format where 1.0 x 102 would be written as 1.0E2 no spaces allowed

Answer 1

$\text{ Kw = }\lbrack\text{H}_3\text{O}^+\rbrack\lbrack\text{OH}^-\rbrack$$\lbrack\text{OH}^-\rbrack\text{ = }\frac{\text{ Kw}}{\lbrack\text{ H}_3\text{O}^+\rbrack}=\frac{1\times10^{-14}}{1\times10^{-10}}=1\times10^{-4}$

The answer is [OH-] = 1.0E-4