calculate pH for each H3O+ concentration

Question

a) [H3O+] = 1 x 10^-7 M

pH= ?

b) [H3O+] = 0.1 M

pH= ?

c) [H3O+] = 1 x 10^-13

pH= ?

Answer 1

Simply take the negative log of the [H3O+].  That will give you the pH.