Question

Find out the pH of the solution at 25°c
When [OH-] = 1 x 10-5 M
..​

Answer 1

Answer:

$\large\boxed{\sf{pH=9}}$

Explanation:

Given that,

Concentration of hydroxide ion,

• $\left[{OH}^{-1}\right]={10}^{-5}\;M$

Now, we know that,

$\left[{OH}^{-1}\right]\left[{H}^{+}\right]={10}^{-14}$

Therefore, we will get,

$= > \left[{H}^{+}\right] \times {10}^{ - 5} = {10}^{ - 14} \\ \\ = > \left[{H}^{+}\right] = {10}^{ - 14} \times \dfrac{1}{ {10}^{ - 5} } \\ \\ = > \left[{H}^{+}\right] = {10}^{ - 14 + 5} \\ \\ = > \left[{H}^{+}\right] = {10}^{ - 9}$

Therefore, concentration of hydronium ion is ${10}^{-9}\;M$.

Now, we know that,

$\bold\red{pH = -log \left[{H}^{+}\right]}$

Therefore, we will get,

$= > pH = - log( {10}^{ - 9} ) \\ \\ = > pH = - 9 \times - log(10) \\ \\ = > pH = - 9 \times - 1 \\ \\ = > pH = 9$

Hence, the required pH is 9.