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

BOARD

(a) Draw the structures of the following :

(i) ${H}_{3}P{O}_{2}$                                                          (ii) $Br{F}_{3}$

(b) How would you account for the following observations :

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

(ii) Bond dissociation energy of fluorine is less than that of chlorine.

(iii) No chemical compound of helium is known.

(a)  (i) ${H}_{3}P{O}_{2}$ (Hypophosphorous acid)

(ii) $Br{F}_{3}$ ($S{P}^{3}d$ hybridization)

Shape : Bent T-shape

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

(ii) Due to smaller size of F than Cl as a result of which electron-electron repulsions between the lone pairs of electrons are very large than that of Cl, hence bond dissociation energy of ${F}_{2}$ is less than that of $C{l}_{2}.$

(iii) Because the ionization energy of Helium is very high and the empty d-orbitals are also absent in it.

Difficulty Level:

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