Question

Acid rain has a pH value of 3.0, whereas
normal rain has a pH value of 5.6. Calculate
the ratio of the hydronium ion in acid rain to
that in normal rain.

Answer 1

Convert pH 3.0 to (H^+) using pH = -log(H^+).
Convert pH 5.6 to (H^+).
Divide 1st by the 2nd to find the ratio acid/normal

Answer 2

do I just use the moles of H+?

Answer 3

No, the pH needs to be converted to H^+ using the inverse log
Example:
ph = -log[H^+] = 3.0
log [H^+] = -3.0
[H^+] = inv log (3.0)
10^(-3.0)