(a) Account for the following:
(i) Tendency to show -3 oxidation state decreases from $\mathrm{N}$ to $\mathrm{Bi}$ in group 15.
(ii) Acidic character increases from ${\mathrm{H}}_2\mathrm{O}$ to ${\mathrm{H}}_2\mathrm{Te}$.
(iii) ${\mathrm{F}}_2$ is more reactive than ${\mathrm{CIF}}_3$, whereas ${\mathrm{CIF}}_3$ is more reactive than ${\mathrm{Cl}}_2$.
(b) Draw the structure of (i) ${\mathrm{XeF}}_2$ (ii) ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$.
OR
(a) Give one example to show the anomalous reaction of fluorine.
(b) What is the structural difference between white phosphorus and red phosphorus?
(c) What happens when ${\mathrm{XeF}}_6$ reacts with $\mathrm{NaF}$ ?
(d) Why is ${\mathrm{H}}_2\mathrm{S}$ a better reducing agent than ${\mathrm{H}}_2\mathrm{O}$ ?
(e) Arrange the following acids in the increasing order of their acidic character:
$\mathrm{HBr},\mathrm{Hl},\mathrm{HCl},\mathrm{HF}$