Why is bromine water an oxidizing agent?

Bromine water acts as an oxidizing agent primarily due to the high electron affinity of the bromine element. As a member of the halogens, bromine exists as diatomic molecules ($B{r}_2$) that are versatile oxidizing agents capable of undergoing oxidation-reduction reactions.12

In these chemical processes, bromine effectively accepts electrons from other substances, thereby oxidizing them. For instance, bromine water can liberate free iodine from iodide-containing solutions and oxidize sulfurous acid to sulfuric acid. While its oxidizing power is significant, it is generally less powerful than chlorine because the bromide ion experiences weaker hydration than the chloride ion.1