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


Account for the following:

(i) NF3 is an exothermic compound but NCI3 is an endothermic compound.

(ii) HF is not stored in glass bottles but is kept in wax-coated bottles.

(iii) Bleaching of flowers by Cl2 is permanent while that of SO2 is temporary.

(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) HF is highly corrosive and etches glass hence it is kept in wax-coated bottles.

(iii) Chlorine bleaches the material by oxidation hence it is permanent while SO2 bleaches the material by reduction and as the material is exposed to air, it gets oxidised and the colour is restored, hence it is temporary.

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