Question

Which of these substances has the highest pOH?

0.10 M HCl, pH = 1


0.001 M HNO3, pH = 3


0.01 M NaOH, pH = 12

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.