Question

The pH values for three different solutions are $13,11$ and $9$. Arrange these pH values in the decreasing order of hydronium or $H^{+}$ ion concentration.

• A. $13>11>9$
• B. $9>11>13$
• C. $9>13>11$
• D. $11>13>9$

Answer 1

Answer: (B)

$9>11>13$

We know $pH=-log\left[H^{+}\right]$

Hydronium ion concentration $=$ ${10}^{-pH}$
Hydronium ion concentration in $pH=13$ is ${10}^{-13}$, in $pH=11$ is ${10}^{-11}$ and in $pH=9$ is ${10}^{-9}$.

Therefore, the pH values in the decreasing order of hydronium or $H^{+}$ ion concentration are as follows:

$9>11>13$