Introducing Nitrogen

Nitrogen is totally unreactive in our atmosphere…

The Haber Process Be able to describe the manufacture of ammonia by the Haber process, and remember the essential conditions: (i) a temperature of about 450 °C (ii) a pressure of about 200 atmospheres (iii) an iron catalyst N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g) Remember where we get nitrogen and hydrogen from in the manufacture of ammonia. manufacture of fertilisers, explosives and cleaning fluids.

The Haber Process N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g) The air Hydrogen is obtained from natural gas (methane) or the cracking of hydrocarbons. CH 4 + H 2 O  CO + 3H 2

The Haber Process N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g) If we want to make ammonia in industry, should we use high pressure or low pressure? 4 molecules2 molecules We actually use 200 atmospheres

The Haber Process N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g) If we want to make ammonia in industry, should we use high or low temperature? Forward reaction is EXOTHERMIC Backward reaction is ENDOTHERMIC We actually use 450 °C 450 °C is a compromise. Remember, reactions are faster at higher temperatures. We have to use an iron catalyst

The Haber Process On cooling the ammonia liquefies and is removed. Why is this? N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g)