Question

On heating copper sulphate crystals (blue) at a very high temperature, it changes to white coloured substance 'X'. Number of water molecules lost by one formula unit of copper sulphate during heating is ​

Answer 1

X =CuSO₄ (anhydrous copper suphate)

5 molecules of water

Explanation:

When we heat copper sulphate crystals at a very high-temperature white color anhydrous copper suphate is obtained.

CuSO₄.5H₂O + Heat → CuSO₄ + 5H₂O

From the reaction, we can conclude that 5 molecules of water were lost during heating.

Answer 2

Number of water molecules lost by one formula unit of copper sulphate during heating is five.

1. Hydrated copper sulphate has chemical formula CuSO4.5H2O. Thus, as per the formula, one formula unit copper sulphate has 5 molecules of water attached to it.
2. On heating, this loss of water molecules is accompanied with change in colour of salt.
3. Regaining of these water molecules again changes the colour of salt to blue.