Question

Calculate the $pOH$ of a solution at $25^{\circ }C$ that contains $1\times 10^{-10}M$ of hydronium ion.

• A. 7.000
• B. 4.000
• C. 9.000
• D. 1.000

Answer 1

Answer: (B)

$[H_3{O}^{+}]=[H^{+}]=10^{-10}$
$pH+pOH=14$
$pH=-\log [H^{+}]$
$pH=-\log [10^{-10}]$
$pH=10$
$pOH+10=14$
$pOH=14-10=4$