1.0X10^-7

[Ashlyn Brunette 1I]

Hi,
in lecture today, we were discussing Kw and Lavelle used 1.0X10^-7 for the concentration of H3O+ and OH- to get 1.0X10^-14 for Kw. Where did the 1.0x10^-7 come from? Is that just an experimental value they got from measuring the concentration?

[Deep Mehta]

1.0 x 10^-7 indicates the concentrations of both H3O+ and OH- because at this point, this indicates that the substance is completely neutral. If you were to convert 1.0 x 10^-7 into pH (-log[1 x 10^-7]), you would notice that the pH and pOH are both 7 which add up to pKw of 14. The same thing applies to Kw = (Ka)(Kb). Hope this helps!