## Inverse Relationship Between H3O+ and OH- [ENDORSED]

janavi_patel_2K
Posts: 20
Joined: Wed Sep 21, 2016 2:59 pm

### Inverse Relationship Between H3O+ and OH-

On Pg. 150-151 of the course reader, there is a calculation completed in order to calculate pH and pOH. The equation is Ba(OH)2 --> Ba^2+ + 2OH-. One of the first steps was to find the concentration in H3O+. I understand the how the value was obtained, but I do not understand why the concentration of H30+ was calculated if it is not in the chemical equation.

Kareem
Posts: 18
Joined: Wed Sep 21, 2016 3:00 pm

### Re: Inverse Relationship Between H3O+ and OH-

If you can calculate the concentration of OH- you can calculate the concentration of H3O+. Their concentrations multiply out to 1x10^-14.

Posts: 37
Joined: Wed Sep 21, 2016 2:56 pm
Been upvoted: 1 time

### Re: Inverse Relationship Between H3O+ and OH-  [ENDORSED]

H3O+ and OH- are in equilibrium with water. 2H20<-->H3O+ + OH-. Therefore their Kc(written as Kw)=[H3O+][OH-]=1x10^-14. Therefore, in any aqueous system, their concentrations will equal 1x10^-14. Therefore, obtaining the concentration of OH- in the equations above will allow you to obtain the concentration of H3O+.