# NEET Chemistry The p-Block Elements (XII) Questions Solved

BOARD

(a) Draw the structures of the following :

(i) $Xe{F}_{4}$                                                 (ii) ${H}_{2}{S}_{2}{O}_{7}$

(b) Explain the following observations :

(i) Phosphorus has a greater tendency for catenation than nitrogen.

(ii) The negative value of electron gain enthalpy is less for fluorine than that for chlorine.

(iii) Hydrogen fluoride has a much higher boiling point than hydrogen chloride.

(a) (i) $Xe{F}_{4}$ :

Shape : Square planar

(ii) ${H}_{2}{S}_{2}{O}_{7}$ :

(b) (i) The bond strength of P-P is more than N-N, therefore phosphorus shows more tendency for catenation than nitrogen.

(ii) Because of small size of flourine atom and strong electron-electron repulsions in its compact 2p orbitals.

(iii) Hydrogen fluoride (HF) has higher boiling point than HCl due to extensive intermolecular hydrogen bonding while HCl doesn't show this H-bonding.

Difficulty Level: