At ordinary temperatures hydrobromic acid is a colourless gas which fumes strongly in moist air, and has an acid taste and reaction.
On the other hand, they may give off unhealthy fumes and produce unpleasant odours.
The gas fumes strongly in moist air, and it is rapidly dissolved by water, one volume of water at o° C. absorbing 503 volumes of the gas.
With a little water it forms arsenic oxychloride, AsOCl, and with excess of water it is completely decomposed into hydrochloric acid and white arsenic. It combines directly with ammonia to form a solid compound variously given as AsCl3.3NH3 or 2AsCl3.7NH3, or AsCl3.4NH3 Arsenic trifluoride, AsF3, is prepared by distilling white arsenic with fluorspar and sulphuric acid, or by heating arsenic tribromide with ammonium fluoride; it is a colourless liquid of specific gravity 2.73, boiling at 63° C; it fumes in air, and in contact with the skin produces painful wounds.
It fumes strongly in moist air, giving hydrochloric acid and phosphoryl chloride, POC13; with water it gives phosphoric and hydrochloric acids.