Question

Identify the odd one out with respect to valency

• A. (a) Sulphide
• B. (b) Oxide
• C. c) Zincate
• D. (d) Carbide

Answer 1

The correct option is D

(d) Carbide

• Group of atoms bound together with a specific charge and behave as an ion is called a polyatomic ion or radical.
• The ions are charged atoms .
• There are two types of ions, positive ion (cation) eg NH₄ + (ammonium ion) and negative ion (anion) eg Sulphide ion S^-2.

Explanation for correct answer

(d)

• Carbon is a tetravalent element. Valency of carbide ( C^-4. ) is 4
• eg: aluminium carbide (Al₄C₃). in this compound Valency of aluminium is 3 and that of carbon is 4

Explanation for incorrect answer

• (a) Sulphide (S^-2) eg: hydrogen sulphide (H₂S).valency -2
• (b) Oxide (O^-2) eg: water (H₂O) .valency -2
• (c) Zincate (ZnCO₂)^-2 eg: sodium zincate (Na₂ZnCO₂ ) valency -2
• All are bivalent radicals.

Hence, the correct option is D.