Mercury(II) oxide

Mercury(II) oxide is a chemical compound. Its chemical formula is HgO. It has mercury and oxide ions. The mercury is in the +2 oxidation state.
Properties.
It is a red or yellow solid. It is very toxic and corrosive. It reacts violently with some reducing agents, as it is an oxidizing agent. It reacts with acids to make other mercury(II) salts like mercury(II) chloride. It breaks down when heated to make mercury and oxygen.
Preparation.
It can be made by heating mercury and oxygen at . It can also be made by heating mercury(II) nitrate. This makes the red form. The yellow form is made by reacting a mercury(II) salt with a strong base.
Uses.
It can be used to make other mercury(II) salts. It is used in mercury batteries. It is much cheaper than the silver(I) oxide used in silver oxide batteries.