Question

Which of these substances has the highest pOH?

Answer 1

0.10 M HCl, pH = 1                  A

Answer 2

Answer: 0.10 M HCl, pH = 1  

Explanation: pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration and pOH is calculated by taking negative logarithm of hydroxide ion concentration.

$pH=-\log [H^+]$

$pOH=-log{OH^-}$

$pH+pOH=14$

1. 0.10 M $HCl$, pH=1

$1+pOH=14$

$pOH=13$

2. 0.001 M $HNO_3$, pH=3

$3+pOH=14$

$pOH=11$

3. 0.01 M $NaOH$, pH=12

$12+pOH=14$

$pOH=2$

Thus 0.10 M HCl, pH = 1  has highest pOH.