Question

Explain the effect of heat on blue crystals of copper sulphate

Answer 1

• Substances that contain water of crystallization are called hydrated salts. Example- Copper sulphate pentahydrate$({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O})$
• Water of crystallization gives the shape and color to the salts.
• Hydrated copper sulphate$({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O})$ is blue in color as it is having water of crystallization.
• Substances that do not contain water of crystallization are called anhydrous salts. Example- Potassium chloride$\left(\mathrm{KCl}\right)$
• When hydrated copper sulphate $({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O})$ is heated, it becomes anhydrous and the blue color fades and changes into white color.