Ammonia is manufactured from nitrogen and hydrogen by the Haber process: N₂(g) + 3H₂(g) ⇌ 2NH₃(g) The forward reaction is exothermic. The conditions used in the Haber process are: - 200 atmospheres pressure - 450 °C - iron catalyst Use the equation and your knowledge of reversible reactions to explain why these conditions are used in the Haber process. To get full marks, you must consider both yield and rate of reaction in your answer.

200 atmospheres pressure

• high pressure gives a yield of ammonia.

• 4 moles of gas become 2 (or moles of gas in products)

• high pressure to maintain

• a higher pressure will cause the rate to be

• particles in same volume so more collisions.

Ammonia is manufactured from nitrogen and hydrogen by the Haber process: N₂(g) + 3H₂(g) ⇌ 2NH₃(g) The forward reaction is exothermic. The conditions used in the Haber process are: - 200 atmospheres pressure - 450 °C - iron catalyst Use the equation and your knowledge of reversible reactions to explain why these conditions are used in the Haber process. To get full marks, you must consider both yield and rate of reaction in your answer.

450 °C

high temperature the rate of reaction

• particles are moving faster so there are more collisions.

• The particles have more energy so a greater proportion of the collisions exceed the energy and are successful.

forward reaction is so a high yield of ammonia requires a temperature

450 °C is a compromise temperature

Too low a temperature causes the of reaction to be too slow and too high a temperature causes the to be too low.

Ammonia is manufactured from nitrogen and hydrogen by the Haber process:

N₂(g) + 3H₂(g) ⇌ 2NH₃(g) The forward reaction is exothermic.

The conditions used in the Haber process are:

200 atmospheres pressure

450 °C

iron catalyst

iron catalyst

• a catalyst up the reaction (by providing an pathway of lower energy so that a greater proprtion of the collisions exceed the activation energy so there are more sucssful collisions)

• an iron catalyst allows a temperature to be used (saving energy and so is more )

• iron catalyst increases the rate of reaction equally in both reactions so does not affect the (allows equilibrium to be achieved more quickly).

Note the underacted nitrogen and hydrogen is recycled separated using fractional distillation which improves the sustainability