Intermediate Topic 648 of 1102 Inorganic Chemistry
Oxides of Nitrogen
N2O, NO, NO2, N2O3, N2O4 and N2O5 show nitrogen's oxidation states from +1 to +5.
In-depth explanation of Oxides of Nitrogen
Nitrogen forms several oxides in which its oxidation state runs from +1 to +5: N2O at +1, NO at +2, N2O3 at +3, NO2 at +4 and N2O5 at +5. Nitric oxide has an unpaired electron, making it a free radical, and it acts as a signalling molecule in the body. Nitrogen dioxide is a brown, toxic gas that dimerises to N2O4 and contributes to smog and acid rain. Nitrous oxide, laughing gas, is an anaesthetic and a potent greenhouse gas. Oxides are commonly made by oxidizing ammonia or by decomposing nitrates.
Going deeper: Oxides of Nitrogen
Key ideas: N2O (+1, laughing gas), NO (+2, paramagnetic, odd electron), N2O3 (+3), NO2 (+4, brown, dimerizes to colorless N2O4), N2O5 (+5, anhydride of nitric acid). NO forms in engines and lightning, oxidizes in air to NO2. 2NO2 as N2O4 equilibrium shifts to NO2 on heating. Acidic oxides: NO2 + H2O gives HNO3 + HNO2, disproportionation. N2O and NO are neutral.
Common mistakes and connections: Students count N2O5 as having an N-N bond; it is O2N-O-NO2. Another mistake is calling NO acidic; it is neutral. Oxidation state of N in each should be tracked for redox questions. NO2 and NO make smog and acid rain, and NO destroys ozone catalytically. Links to nitric acid, pollution and equilibrium of dimerization.
Visualization of Oxides of Nitrogen
Oxidation state of nitrogen across its five common oxides, from +1 in laughing gas to +5 in N2O5. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Nitric oxide reacts with oxygen to give brown nitrogen dioxide: 2NO + O2 giving 2NO2.
Frequently asked questions about Oxides of Nitrogen
What is Oxides of Nitrogen?
N2O, NO, NO2, N2O3, N2O4 and N2O5 show nitrogen's oxidation states from +1 to +5.
Is Oxides of Nitrogen a beginner, intermediate or advanced topic?
Oxides of Nitrogen is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
What should I learn before Oxides of Nitrogen?
Study these earlier topics in Inorganic Chemistry first: Carbides, Nitrogen Family, Ammonia.
What comes after Oxides of Nitrogen?
The next topics in Inorganic Chemistry are Nitric Acid and Phosphorus Allotropes.
Can I practise Oxides of Nitrogen with quizzes?
Yes. The interactive lesson includes a self-check question on Oxides of Nitrogen, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Oxides of Nitrogen fits in Inorganic Chemistry
Oxides of Nitrogen is topic 33 of 113 in Inorganic Chemistry.