Question

What is the colour of copper sulphate crystals? What happens when its heated?

Answer 1

Hint: Copper sulphate exists as $CuS{O_4}.5{H_2}O$, the ${H_2}O$ is known as water of crystallization. Whenever we heat any substance the first thing evaporates is water in the same way when copper sulphate is heated water molecules will evaporate.

Complete step by step answer:
The original colour of copper sulphate is blue in colour when its heated it loses five water molecules present in it which changes the structure of a crystal hence the properties of crystals get changed which includes change in colour.
When copper is heated the colour changes from blue to white as water evaporates.
When five water molecules are present and it's in blue colour it is called as hydrated copper sulphate and then after heating when water molecules get evaporated it is called as anhydrous copper sulphate.
$CuS{O_4}.5{H_2}O$$\xrightarrow{{heat}}$$CuS{O_4} + 5{H_2}O \uparrow $
 $\text{ (blue) (white)}$

Note: Salts after evaporation of water molecules are known as anhydrous salts. Copper sulphate after heating water evaporates and it becomes anhydrous salt from hydrous copper sulphate salt.Copper sulphate is used in agricultural industries as well as medical industry.