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

BOARD

(a) Give reasons for the following :

(i) Bond enthalpy of F2 is lower than that of Cl2.    

(ii) PH3 has lower boiling point than NH3.

(b) Draw the structures of the following molecules :

(i) CIF3                                 (ii) HPO33                            (iii) XeF4

(a) (i) 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 enthalpy of F2 is less than that of Cl2.

(ii) PH3 has lower boiling point than NH3 because PH3 cannot form hydrogen bonds like NH3.

(b) (i) CIF3 :

Shape : Bent T-shape

(ii) HPO33 : Cyclotrimetaphosphoric acid 

(iii) XeF4 :

Shape : Square planar

Difficulty Level: