Halogens in water. The aqueous solubility of the halogens is poor. From left: chlorine, bromine, and iodine. Chlorine gas dissolves to produce a pale yellow-green liquid. It also reacts with the water to form hydrochloric acid and hypochlorous acid. Bromine is a volatile orange liquid. Bromine vapour (gas) is seen rising from the surface of the water. The bromine also reacts with the water to form hydrogen bromide and hypobromous acid. Iodine is a purple-black solid. It will form an aqueous solution if conditions are right for the triiodide ion to form. The colour varies depending on the exact conditions, but can be reddish-brown as here.