Which acid is stronger between HCl and H2SO4?

Which acid is stronger between HCl or H2SO4?

This is not a completely straightforward question. HCl and H2SO4 are categorized asstrong acids. That means that they are about 100% ionized in water. In water all of the strong acids are of essentially the same strength. This happens because water is a leveling solvent. In water the strongest acid that can exist is H3O+, or hydronium ion. Thus, in order to be able to tell which of the strong acids above is stronger you have to use a different solvent for the acids like, for instance, CH3COOH, or 100% pure acetic acid. In solvents such as this we can see which of the strong mineral acids is actually the strongest. In this case, the references below reveal that HCl is a bit stronger than H2SO4, although in water they are essentially the same strength.

The ionization of each of the acids is written below.

HCl(g) + H2O(l) --> H3O+(aq) + Cl-(aq)

H2SO4(l) + H2O(l) --> H3O+(aq) + HSO4-(aq)