Question

How does hydroxyl ion concentration decrease on addition of acid to water

Answer 1

Dear Student,

If we talk about the case of Pure water it is represented as:

$\left[H_3{O}^{+}\right]\left[O{H}^{-}\right]={10}^{-14}$
It means that the product of the pair concludes to a constant value.
Now if we add Acid to water the concentration of $\left[H_3{O}^{+}\right]$ increases as result the concentration of $\left[O{H}^{-}\right]$ have to decrease to stable the constant value.Hence concentration of hydroxyl ion decreases on addition of acid to water.

​​​I ​​​​Hope it clarifies your query.

Regards