Why is KI oxidized by H2SO4, whereas NaBr isn't oxidised?

Answer 1

Even though iodide and bromide are in the same halogen group, their chemistry can be similar on the one hand, but not similar on the other. Iodide can be readily oxidized while bromide cannot. In addition to its very strong acidity, H2SO4 is also an oxidizing compound. It does not have sufficient oxidation activity against bromide, but it is more than enough to oxidize iodide.