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

BOARD

Explain the following facts giving appropriate reasons in each case :

(i) NF3 is an exothermic compound whereas NCl3 is not.

(ii) All the bonds in SF4 are not equivalent.

(i) The bond energy of F-F bond is lower than that of N-F bond so NF3 is an exothermic compound. On the other hand bond energy of Cl-Cl bond is higher than that of N-Cl bond so NCl3 is an endothermic as well as unstable compound.

(ii) SF4 has trigonal bipyramidal structure in which one position of equitorial is occupied by a lone pair of electrons. Sulphur undergoes sp3d hybridisation and has sea-saw geometry.

 

Difficulty Level:

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