What is the [OH-] in a solution that has a pH = 9.23? * O 1.7x10^5
O 8.2x10^-9
1.7x10^--5 M.

   1.7x10^-5

Explanation:

pH + pOH = 14

14 - pH = pOH

14 - 9.23 = 4.77

pOH =4.77

[OH-] = 10^-pOH

         = 10^-4.77

         = 1.698243x10^-5

         = 1.7x10^-5

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)