Question

The covalency of central atom is maximum in:

• A. $HCN$
• B. $N{H}_4^{+}$
• C. $PC{l}_5$
• D. $H_{2}O$

Answer 1

The correct option is C $PC{l}_5$

First, note that covalency = number of bonds formed.

In $HCN$, the carbon atom forms 1 bond with hydrogen and 3 bonds with nitrogen so covalency = 4. In ammonium ion, nitrogen atom forms 1 bond with each hydrogen. So, covalency = 4. In phosphorus pentachloride, the phosphorus atom forms 1 bond with each chlorine atom. So, covalency = 5. In a water molecule, the covalency of oxygen = 2.