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Kw - applies to solutions other than 100% water?

Posted: Wed Jan 23, 2019 9:09 pm
by Dayna Pham 1I
For 12.21 in the Sixth Edition, we are suppose to solve for either [H3O+] or [OH-] using the Kw relationship, [H3O+][OH-] = 10^-14. Can we use this relationship to solutions other than 100% water? I thought that Kw was only for water but it doesn't say in the question whether the solution is water-based or not.

Re: Kw - applies to solutions other than 100% water?

Posted: Wed Jan 23, 2019 9:15 pm
by Anushi Patel 1J
I think we are supposed to assume the solvent is water. Also, I think you can always use Kw to relate [H3O+] and [OH-].

Re: Kw - applies to solutions other than 100% water?

Posted: Wed Jan 23, 2019 9:16 pm
by Kyle Golden Dis 2G
The question implies that it is about water since it has hydroxide and hydronium ion.

Re: Kw - applies to solutions other than 100% water?

Posted: Wed Jan 23, 2019 10:27 pm
by Angela Grant 1D
Kw implies that the solution is water since the expression represents the autoprotolysis of water