Its aqueous solution gradually decomposes with evolution of oxygen, behaves as a strong oxidant, and liberates iodine from potassium iodide.
Strong sulphuric acid in contact with it liberates first nitric acid and later oxides of nitrogen, leaving a charred residue or a brown solution according to the quantity of acid.
As the current flows it decomposes the liquid and liberates oxygen and hydrogen gases, which escape.
The aqueous solution of this salt liberates carbon dioxide on exposure to air or on heating, and becomes alkaline in reaction.
It attacks most metals readily, usually with production of a nitrate or hydrated oxide of the metal and one or other of the oxides of nitrogen, or occasionally with the production of ammonium salts; magnesium, however, liberates hydrogen from the very dilute acid.