If #pH=7.5#, what is #pOH#, and what is #[HO^(-)]#?

1 Answer
Nov 23, 2016

Answer:

#pH=-log_10[H_3O^+]#

Explanation:

And #pOH=-log_10[HO^-]#

We know that under standard condtions, #pH+pOH=14#.

And where #pH<7#, an acidic solution is specfied; #pH>7#, an basic solution is described. What sort of solution do we have at #pH=7#?

Given a calculator, those bits of information are all we need to solve these problems:

If #pH=7.5#, then #pOH=14-7.5=6.5#;

by definition, #[H_3O^+]=10^(-7.5)*mol*L^-1#, #[HO^-]=10^(-6.5)*mol*L^-1#. And the solution is slightly basic due to the preponderance of #[HO^-]# ions.

I invite you to complete the remainder of the table.