A beaker contains a solution of substance'A' precipitation of substance 'A' takes place when small amount of 'A' is added to the solution. The solution is………

A beaker contains a solutions of copper sulphate . Recipitaion of copper sulphate takes place when small amount of it added to ________ solution .

What is reaction takes place when Al is added to KOH solution?

Effervescence takes place when sodium carbonate solution is added to

A white powder when strongly heated gives of brown fumes. A solution of this powder gives and yellow precipitate with a solution of KI. When a solution of barium chloride is added to the solution of powder , a white precipitate result . This white powder may be -