Question

What is a solution considered when it has an equal number of hydrogen and hydroxide ions?

Answer 1

It is considered to be neutral with respect to `pH`.

Explanation:

`2H_2O rightleftharpoons HO^(-) + H_3O^+`

As you know, water undergoes autoprotolysis as represented in the given reaction. Under standard conditions, `[HO^-]=[H_3O^+]`, which specifies a condtion of neutrality. To put numbers to this equation, `K_w=[H_3O^+][""^(-)OH]=10^-14`.

How do I use this equation to define `pH`?