What is the logarithmic concentration of the hydroxide ion in aqueous solution?

1 Answer
Jan 26, 2016

I presume you mean #pOH#?

Explanation:

We would calculate #pOH# the same way we calculate #pH#. That is #pOH# #=# #-log_(10)[OH^-]#, where #[OH^-]# is the concentration of hydroxide ion.

Given that #10^-14# #=# #[H_3O^+][OH^-]#,

then #log_(10)10^(-14)# #=# #log_(10)[H_3O^+]# #+# #log_(10)[HO^-]#

And thus #14# #=# #pH + pOH# (because by definition #log_(10)10^(-14)# #=# #-14#.

So you need to find hydroxide (or acid) concentration, and take its negative logarithm to the base 10.