Question

Which pH is more acidic, a pH of 3, a ph of 7, or a ph of 9?

Answer 1

The solution whose `pH=3` is MOST acidic.

Explanation:

`pH` `=` `-log_10[H_3O^+]`.

And thus `[H_3O^+]=10^(-pH)`. Clearly `10^(-3)>10^(-7)>10^(-9)`; we see here orders of magnitude difference.