## Chemistry: The Central Science (13th Edition)

$HClO_3$ is the stronger acid.
$HClO_3$ is one of the 7 common strong acids. Since $HClO_3$ completely dissociates in water, and $HClO_2$ doesn't, $HClO_3$ is the stronger. $K_a(HClO_3) > 1$ $K_a(HClO_2) \approx 1.1 \times 10^{-2}$