'''Sulfuric acid''' (H<sub>2</sub>SO<sub>4</sub>) is a [[strong acid|strong]] [[diprotic]] acid. This is unusual as it is the only known strong diprotic acid. It has a pKa of -3. This is not exact as the pKa values of strong acids are not well defined. | '''Sulfuric acid''' (H<sub>2</sub>SO<sub>4</sub>) is a [[strong acid|strong]] [[diprotic]] acid. This is unusual as it is the only known strong diprotic acid. It has a pKa of -3. This is not exact as the pKa values of strong acids are not well defined. |