The presence of chloric(I)acid makes the properties of chlorine water different from those of gaseous chlorine,just as aqueous sulphur dioxide is very different from the gas. Chloric (I)acid is a strong oxidising agent,and in acid solution will even oxidise sulphur to sulphuric acid;however,the concentration of free chloric(I)acid in chlorine water is often low and oxidation reactions are not always complete. Nevertheless when chlorine bleaches moist litmus,it is the chloric(I)acid which is formed that produces the bleaching. The reaction of chlorine gas with aqueous bromide or iodide ions which causes displacement of bromine or oidine (see below)may also involve the reaction