Answer
$H_2SO_4$ is the stronger oxyacid.
Work Step by Step
- $H_2SO_4$ and $H_2SO_3$ have the same central atom: $S$;
Therefore, the difference here will be the number of oxygen connected to the central atom.
$H_2SO_4$ has 4 oxygen.
$H_2SO_3$ has 3 oxygen.
So: $H_2SO_4$ is more acidic.
