Chemistry: The Central Science (13th Edition)

Since $HBr$ completely dissociates in aqueous solution and $HBrO$ doesn't , $HBr$ will be the stronger acid. *$HBr$ is one of the common strong acids. $K_a (HBrO) = 2.8 \times 10^{-9}$ $K_a(HBr) \approx 10^9$