Q. Nitrogen forms largest oxides as it is capable of forming stable multiple bonds with oxygen. They range from N2O (O.S of nitrogen +1) through NO,N2O3,N2O4 to N2O5 (O.S of nitrogen +5).
The following points are important regarding the oxides of nitrogen.
(a) All oxides of nitrogen except N2O5 are endothermic because large amount of energy is required to dissociate the stable molecule of oxygen and nitrogen.
(b) The small electronegativity difference between oxygen and nitrogen makes N-O bond easily breakable to give oxygen and hence oxides of nitrogen are said to be better oxidizing agents.
(c) Except N2O5, all are gases at ordinary temperature. N2O3 is stable only at a lower temperature (253 K).
(d) Except N2O and NO which are neutral oxides, all are acidic oxides that dissolve in water forming corresponding oxyacids.
(e) They are also a good example of illustrating the concept of resonance.
The gas which is acidic in nature is ________.