Oxides of Nitrogen (named)

Named oxides: N₂O · NO · NO₂. Oxidation of NO: 2NO + O₂ → 2NO₂. NOₓ = nitrogen oxides in pollution discussions. Colour cue (school): NO₂ is brown; NO is colourless. Do not confuse nitrogen oxides with SO₂ / SO₃ (sulphur oxides).

Nitrogen forms several oxides; three names dominate Class 11 answers. N₂O (dinitrogen monoxide / nitrous oxide), NO (nitrogen monoxide / nitric oxide), and NO₂ (nitrogen dioxide) differ in formula and oxidation state of nitrogen. A standard reaction to learn is the conversion of NO into NO₂ in air: 2NO + O₂ → 2NO₂. That step matters environmentally because vehicle and combustion emissions can release NO, which then forms brown NO₂. Collectively, nitrogen oxides in the atmosphere are discussed as NOₓ pollution. Exam tip: name formulas correctly, write the NO → NO₂ equation with balancing, and state that NOₓ is a pollution concern. Keep sulphur dioxide chemistry separate.

Three oxides to name: N₂O, NO, and NO₂. NO can react with oxygen to make NO₂. NOₓ means nitrogen oxides that pollute the air. NO₂ is the brown gas often mentioned in pollution stories.

Memorise names and formulas: N₂O, NO, NO₂. Balance 2NO + O₂ → 2NO₂. Link combustion / traffic sources to NOₓ emissions and air-quality problems (smog / acid rain themes as in the syllabus narrative). Colour and reactivity cues help recognition: NO₂ is brown; the NO-to-NO₂ oxidation explains why exhaust gases can darken on standing in air.

Track nitrogen oxidation states across the named oxides (N₂O +1, NO +2, NO₂ +4 in the usual school assignment). The NO + O₂ reaction is a redox process producing NO₂. In pollution chemistry, NOₓ participates in photochemical cycles; school answers need names, the balanced oxidation equation, and environmental significance rather than full atmospheric modelling.

N₂O · NO · NO₂ · 2NO + O₂ → 2NO₂ · NOₓ = pollution oxides of nitrogen.