Question

What is the pH of a 0.003 M KOH solution?

Answer 1

`pH approx 11.5`

Explanation:

When put in water, the `KOH` dissolves into `K^(+)` and `OH^(-)` ions, with the latter increasing the `pH` of the solution.
As hydroxides can be considered strong bases, it will completely dissociate into the water solution, and form an equal amount of moles of hydroxide ions:

0.003 mol of `OH^(-)`.

Now,

`pOH=-log [OH^(-)]`
`pOH=2.522`

And if we assume this is done under standard conditions:

`pOH+pH=14`
`pH=14-2.522`
`pH approx 11.5`