Question

An aqueous solution has an h3o+ concentration of 4.4×10-2 m. calculate [oh–] for this solution.

Answer 1

first   calculate  Ph
Ph=  -log (H3O+)
Ph=-log( 4.4  x10^-2)=  1.4

Ph  +Poh=14
Poh  is  therefore= 14  - 1.4=12.6

Oh-   concentration  is  calculated   as  follows
1 x10^  -POh
that  is  1  x10^-12.6   which  is=  2.5  x10^-13