(a) Complete the following chemical equations: (i) XeF4 + SbF5 → (ii) Cl2 + F2 (excess) → (b) Explain each of the following: (i) Nitrogen is much less reactive than phosphorus. (ii) The stability of +5 oxidation state decreases down group 15. (iii) The bond angles (O−N−O) are not of the same value in NO₂⁻ and NO₂⁺.

a) i) XeF4 or xenon tetrafluoride reacts with SbF5 which is an Lewis acid and forms adduct - XeF4 + SbF5 → [XeF3]⁺ + [SbF6]⁻
ii) Cl2 + 3F2 → 2ClF3
B) i) Nitrogen is much less reactive than phosphorus as it exists as N2 in which 2 nitrogen atoms are bonded with a triple bond and are stable.
ii) The stability of +5 oxidation state decreases down the group due to inert pair effect.
iii) NO₂⁺ has more bond angle (180 degrees) than NO₂⁻ because NO₂⁺ has no lone pairs which do not disturb the regular bond angle of 180 degrees, but whereas in NO₂⁻ there is one lone pair so the l.p and b.p repulsion leads to a decrease in bond angle from the regular bond angle of 180°.