Mercury(II) bromide

Mercury(II) bromide, also known as mercuric bromide, is a chemical compound. Its chemical formula is HgBr2. It has mercury and bromide ions in it. The mercury is in its +2 oxidation state.
Properties.
Mercury(II) bromide is a colorless solid. It is very toxic and similar to mercury(II) chloride. It can form explosive mixtures with potassium. It also reacts violently with indium at high temperatures. It is corrosive. 
Preparation.
It can be made by reacting mercury(II) oxide with hydrobromic acid or by disproportionation of mercury(I) bromide.
Uses.
It is used as a reagent in a reaction in organic chemistry. It is also used to test for arsenic. The arsenic is reacted with hydrogen to make arsine, which reacts with mercury(II) bromide to turn it yellow or brown.