Question

When a process ‘X’ is applied to anhydrous copper sulphate, it turns blue. Here the process ‘X’ represents *

(a) heating at 150°C

(b) heating at 110°C

(c) dissolution in water

(d) all of these​

Answer 1

Answer:

the process X is dissolution in water because when a i dressed salt is dissolved in water it comes back to its original colour

Answer 2

Answer:

When a process ‘X’ is applied to anhydrous copper sulphate, it turns blue. Here the process ‘X’ represents * (c) Dissolution in water

Explanation:

• In Pentahydrate of copper sulphate( CuSO₄.5H₂O) or hydrated copper sulphate. The five water molecules of crystallisation (or water of hydration) indicate the presence of five water molecules in copper sulphate crystals.

• When copper sulphate pentahydrate is heated, evaporation causes the water of crystallisation to be lost. Hydrated copper sulphate is converted to anhydrous copper sulphate salt during crystallisation. Crystals of hydrated copper sulphate are blue in colour. Crystals become colourless anhydrous crystals when heated. If heating is left unattended, anhydrous copper sulphate decomposes into the dark-colored copper (II) oxide (cupric oxide).
• Anhydrous copper sulphate on dissolution with water becomes hydrated and turns blue when water is added.

           CuSO4 + 5 H₂O ⇒ CuSO4.5H₂O ( blue colour)