5.0 x 10-9 M H3O+ and 2.0 x 10-6 M OH-
Explanation:
To find H3O+, do the following:
pH = -log[H3O+]
-pH = log[H3O+]
antilog -(8.3) = antilog log (antilog and log cancel out) [H3O+]
5.0 x 10^-9 = [H3O+]
To find OH, you need to know pOH
pOH = 14 - pH
pOH = 14 - 8.3
pOH = 5.7
To find OH-, use a similar formula to the one above:
pOH = -log [OH-]
-pOH = log [OH-]
antilog - (5.7) = antilog log (antilog and log cancel out) [OH-]
2.0 x 10^-6 = [OH-]