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

1 Answer
Mar 31, 2017

#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#.