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


How would you account for the following:

(i) H2S is more acidic than H2O.

(ii) The N-O bond in NO2- is shorter than the N-O bond in NO3-.

(iii) Both O2 and F2 stabilize high oxidation states but the ability of oxygen to stabilize the higher oxidation state exceeds that of fluorine.

(i) Since the size of sulphur is more than oxygen, S-H bond length increases and hence bond dissociation energy of S-H is less than O-H. Therefore S-H easily loses H+ and thus is more acidic than H2O.

(ii) The resonating structure of NO2- and NO3- show that in NO2- two bonds are sharing a double bond while in NO3-, 3 bonds are sharing a double bond. That's why NO2- has shorter bond than that of NO3-.

(iii) Oxygen stabilizes the highest oxidation state even more than fluorine.

Example : Highest fluoride of Mn is MnF4 whereas highest oxide is Mn2O7. It is due to ability of oxygen to form multiple bonds with the metal atoms.

Difficulty Level:

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