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

BOARD

How would you account for the following:

(i) $NC{l}_{3}$ is an endothermic compound while $N{F}_{3}$ is an exothermic one.

(ii) $Xe{F}_{2}$ is a linear molecule without a bend.

(iii) The electron gain enthalpy with negative sign for fluorine is less than that for chlorine, still fluorine is a stronger oxidising agent than chlorine.

(i) F is more electronegative than Cl.

The difference in the electronegativity between N and F is much more than the difference between     electronegativity of N and Cl. So there is need of much more energy to break the N-F bond.

(ii) In $Xe{F}_{2}$ there are 2 bond pairs and 3 lone pairs and thus show $s{p}^{3}d$ hybridization. It has linear       geometry.

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

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