Inorganic: Nitrogen & Sulfur

Why is nitrogen unreactive?

1) N2 triple bond is very strong with high bond dissociation

2) Large amount of energy needed to break the bond

3) Non-polar molecule

Displacement of ammonia and its uses

• Ammonium salt + Base → Ammonia gas + Salt + Water

1) Nitric acid

2) Inorganic fertilisers

3) Nylon

4 Explosives

Oxides of Nitrogen formation

1) Natural: During lightning

2) Man-made: In car engines

3) Catalytic convertors: Exhaust gases passed through catalytic convertors containing a catalyst (platinum/palladium/nickel) helping to reduce oxides to nitrogen.

4) Catalysis of SO2 and SO3: 2NO + 2O2 → 2NO2 which is then rapidly re-oxidised to NO2 + SO2 → SO3 + NO

Formation of acid rain

1) SO₃ + H₂O → H₂SO₄

2) 2NO₂ + H₂O → HNO₃ + HNO₂

Combustion pollutants formation

• Nitrogen oxide (NO): N₂ and O₂ in the engine

→ Atmospheric oxides of nitrogen (NO & NO₂) can react with unburned hydrocarbons to form peroxyacetyl nitrate (PAN) which is a component of photochemical smog

• Carbon monoxide (CO): source: incomplete combustion of hydrocarbon fuel, toxic effect on haemoglobin