Question

Explain the following situations :
(i) In the structure of `HNO_(3)` molecule , the N-O bond (121 pm) is shorter than N-OH bond (140pm).
(ii) `SF_(4)` is easily hydrolysed whereas `SF_(6)` is not easily hydrolysed.
(iii) `XeF_(2)` has a straight linear structure and not a bent angular structure.

Answer 1

Due to smaller size of N-O , than N-O bond length of `HNO_(3)` is smaller than N-H bond length .
(ii) In `SF_(4)` , S is not sterically since it is surrounded by only four F atoms , so attack of `H_(2)O` molecules can take place easily and hence hydrolysis take place . On the other hand , S is sterically protected by six F atoms in `SF_(6)` and does not allow `H_(2)O` molecule to attack the S atoms. Thus `SF_(6)` does not undergo hydrolysis.
(iii) As `XeF_(2)` has 5 pairs (10) electrons around Xe forming a `sp^(3)`d hybridisation. Therefore , its geometry is linear.