Question

13. Match the following.

(a) A ⇢II , B ⇢ III, C ⇢ IV, D ⇢ I

(b) A ⇢ IV, B ⇢ III, C ⇢ I, D ⇢II

(c) A ⇢ III, B ⇢ IV, C ⇢ II, D ⇢ I

(d) A ⇢ III, B ⇢ IV, C ⇢ I, D ⇢ II

Column 1	Column 2
CuSO4	Deliquescent
Na2CO3.10H2O	Hygroscopic
concentrated H2SO4	Efflorescent
ZnCl2	Anhydrous salt

Answer 1

A ⇢ IV Copper sulphate crystals (CuSO₄) lose all of its water during crystallization and become anhydrous copper sulphate, which is white in color.

• Anhydrous salts are salts that have lost their water of crystallization

B ⇢ III When Na₂CO₃.10H₂O is exposed to air, it loses nine water molecules and one water molecule is lost during heating.

• Efflorescent compounds are salts that lose water of crystallization totally or partly when exposed to ambient air.

C ⇢ I Concentrated H₂SO₄ absorbs moisture when exposed to air.

• Deliquescent substances: The chemicals that absorb moisture from the environment when exposed to air are known as deliquescent substances.

D ⇢II Zinc chloride (ZnCl₂) is hygroscopic substance.

The capacity of a substance to adsorb and absorb water from its surroundings is referred to as hygroscopic.

Hence, option (b) is the correct answer.