Sir,An inorganic solid diamide upon heating gives a solid and a gas as the product.This solid when dissolved in copper sulphate solution gives violet colouration. How? Sir,please reply with an positive answer i need your help.

Dear student
For an aliphatic diamide we do biuret test.
When aliphatic diamide is heated at a temperature above its melting point, ammonia is evolved and crystalline biuret is formed. This biuret in alkaline medium gives a violet colour with a drop of copper sulphate solution.