Chemistry - 15 Using Our Resources - 15.5 Making Ammonia - the Haber Process & 15.6 The Economics of the Haber Process

Haber process

industrial process for producing ammonia

What are the reactants of the Haber process? [2]

- nitrogen

What are the conditions for the Haber process? [3]

• iron catalyst

• 450°C temperature

• 200 atmospheres pressure

Why do plants need nitrogen?

to make proteins for growth

Why can't plants absorb N₂ from the air?

it is insoluble in water

What form do plants absorb nitrogen in? [2]

• through the roots

• soluble ions

Haber process symbol equation

N₂ + 3H₂ ⇌ 2NH₃

What does the yield of ammonia depend on? [2]

• temperature

• pressure

The forward reaction of the Haber process is (exothermic/endothermic)

exothermic

Where is the hydrogen for the Haber process obtained?

from reacting methane (CH₄) from natural gas with steam at a very high temperature

Obtaining hydrogen from methane word equation:

methane + steam → hydrogen + carbon monoxide

Where is the nitrogen for the Haber process obtained?

from the air

Haber process [5]

• nitrogen and hydrogen are pumped in

• they are compressed and heated in a compressor

• they are pumped through iron catalyst beds

• ammonia

extra hydrogen and nitrogen are recycled through a reflux tube

Ideal conditions for maximum yield in Haber process [2]:

• low temperature

• very high pressure

Why is a low temperature NOT used in the Haber process

and what is done instead? [2]

Why is a very high pressure NOT used in the Haber process

and what is done instead? [2]

What is the function of the iron catalyst?

increases the rate of the Haber process