Recent work indicates the existence of fluoric acid,HFO,formed by the reaction of fluorine and water at 273K. The acid forms colourless crystals. m.p.156 K.is very unstable, and has as expected,very strong oxidising properties.
Chlorine and bromine are both moderately soluble in water,and on crystallisation these solutions give solid hydrates with the halogen molecules occupying cavities within a modified ice lattice. Iodine is only slightly soluble in water in which it forms a brown solution (brown solutions are also formed in ether,alcohol and acetone). The aqueous solutions of chlorine and bromine are good oxidising agents. Chlorine.and to a lesser extent bromine,reacts reversibly with water to give a mixture of acids,for example: