College Chemistry Help please

Question

In a sulfuric acid solution, where [ H3O+] is 0.0001 M, what is the pH value?

A) pH = 12.0

B) pH = 2.0

C) pH = 4.0

D) pH = 11.0

E) pH = 5.0

Answer 1

sulfuric acid is a strong acid (i.e. it ionizes 100%), so the concentration of the acid = the concentration of the hydronium (or hydrogen) ions: 0.00001 M (aka 1 x 10^-5M.) pH = -log [H⁺], so - log [1 x 10^-5] = 5.0, answer E.