In aqueous solution sulphur dioxide (sulphurous acid)is oxidised to sulphuric acid:
Chlorine reacts with some metallic oxides to yield chlorides.for example.
Bromine has many oxidising reactions()and like chlorine it will oxidies sulphur dioxide in aqueous solution to sulphuric acid,and hydrogen sulphide to sulphur.
Iodine has the lowest standard electrode potential of any of the common halogens()and is consequently the least powerful oxidising agent. Indeed,the iodine ion can be oxidised to iodine by many reagents including air which will oxidise an acidified solution of iodide ions. However,iodine will oxidise arsenate()to arsenate()in alkaline solution(the presence of sodium carbonate makes the solution sufficiently alkaline)but the reaction is reversible.for example by removal of iodine.