Ammonia. Bottle of ammonia solution, with yellow safety labelling. It is highly corrosive and harm- ful if swallowed. Ammonia (NH3) is the most important of the nitrogen hydrides and commonly used in chemistry laboratories. It is a colourless strong- smelling gas which is soluble in water, and as here, a saturated solution at room temperature consists of approximately 35% ammonia. Liquid ammonia is a good ionizing solvent.