Topic 2: Nitrogen, Sulphur & Phosphorus

Essential Elements Summary

🌬️ Nitrogen (N)

Group V, Period 2 | Atomic No: 7

Config: 2.5 | Valency: 3 or 5

78% of air

Properties

Colorless, odorless, insoluble, less dense than air, inert (strong N≡N bonds)

Key Reactions

N₂ + 3H₂ ⇌ 2NH₃

Uses

Food preservation, refrigerant, ammonia production, fire prevention

⚡ Sulphur (S)

Group VI, Period 3 | Atomic No: 16

Config: 2.8.6

S₈ molecules

Properties

Brittle yellow solid, insoluble in water, soluble in organic solvents, non-conductor

Key Reactions

S + O₂ → SO₂

Uses

H₂SO₄ production, rubber vulcanization, matches, pesticides

🔥 Phosphorus (P)

Group V, Period 3 | Atomic No: 15

Config: 2.8.5 | Valency: 3 or 5

White & Red allotropes

Properties

Yellow solid at room temp, non-conductor, insoluble in water, MP: 44°C

Key Reactions

Reacts with O₂, halogens, metals

Uses

Fertilizers, matches, toothpaste, phosphoric acid

Nitrogen Compounds

Ammonia (NH₃)

Prep: NH₄Cl + Ca(OH)₂ → CaCl₂ + H₂O + NH₃

Properties: Colorless, pungent smell, very soluble, basic

Uses: Fertilizers, plastics, nitric acid, explosives

Nitric Acid (HNO₃)

Prep: KNO₃ + H₂SO₄ → KHSO₄ + HNO₃

Uses: Fertilizers, explosives, metal purification, dyes

Sulphuric Acid Production

Contact Process (4 Steps)

1

S + O₂ → SO₂

2

SO₂ + O₂ → SO₃

3

SO₃ + H₂SO₄ → H₂S₂O₇ (oleum)

4

H₂S₂O₇ + H₂O → 2H₂SO₄

H₂SO₄ Uses

Fertilizers, car batteries, dehydrating agent, paints, detergents, petroleum refining

Sources

Nitrogen Sources

  • • Air (78%)
  • • Proteins & amino acids
  • • Leguminous plants
  • • Fertilizers (NH₄NO₃)

Sulphur Sources

  • • Volcanic regions
  • • Crude oil
  • • Metal ores
  • • Natural gas (H₂S)

Phosphorus Sources

  • • Bones & egg shells
  • • Earth's crust (phosphates)
  • • Mineral rocks
  • • Banana peels

📚 Group V & VI Elements Summary