(a) Give reasons for the following:
(i) Sulphurin vapour state shows paramagnetic behaviour.
(ii) N-N bond is weaker than P-P bond.
(iii) Ozone is thermodynamically less stable than oxygen.
(b) Write the name of gas released when Cu is added to:
(i) dilute `HNO_(3)` and,
(ii) conc. `HNO_(3)`

Explanation

(a) (i) See Q.29 (i), Paper-2008, Outside Delhi, Set-I, [Page 22].
(ii) See Q. 24 (ii), Paper-2014, Delhi Board, Set-II, [Page 235].
(iii) Ozone is thermodynamically less stable than oxygen because its decomposition into oxygen results in the liberation of heat. Ozone consists of three molecules of oxygen and thus in this it is in unstable state so in order to get stable it gives up its one molecule of oxygen to restore diatomic state.
(b) (i) dilute HNO:See Q. 26 (or) (ii) (a), Paper-2018 (C), [Page 484].
(ii) conc. `HNO_(3): NO_(2)` gas released when Cu is added to con. `HNO_(3)`.
`Cu+4HNO_(3)(conc.)toCu(NO_(3))_(2)+2NO_(2)+2H_(2)O`.