# Theory of acids and bases

## pH of acids

### Exercise 9

In the following multiple-choice questionnaire, $H_3O^+$ is often abbreviated by $H^+$(aq) or even $H^+$ ( which is quite wrong, because $H^+$ is always hydrated in the water! )

Which of the following is NOT a strong acid?

a) $HCl$ b) $HSO_4^-$ c) $HNO_3$ d) $H_2SO_4$

b) is correct