Question

pH of ${10}^{-8}$ M HCl solution

• A. $6.95$
• B. $4.75$
• C. $7$
• D. $8$

Answer 1

The correct option is A $6.95$

Answer (3)
${\left[H^{+}\right]}_{\text{Total}}={\left[H^{+}\right]}_{\text{Acid}}+{\left[H^{+}\right]}_{\text{Water}}$
$={10}^{-8}+{10}^{-7}$
$pH=-\text{log}{\left[H^{+}\right]}_{\text{Total}}=-\text{log}({10}^{-8}+{10}^{-7})$
$=6.95$