Question

If an acid is added to water, what would be the expected direction of the change in the pH of the water?

Answer 1

`pH` will decrease, i.e. become more negative............

Explanation:

By definition, `pH=-log_10[H_3O^+]`

Concentrated `[HCl(aq)]` (34% w/w) is approx. `10*mol*L^-1`, and thus its `pH=-log_10(10)=-(1)=-1`.

Most of the time when a `pH` is quoted, the concentration will give rise to a positive `pH`.