C3.5.1 Making ammonia Flashcards
What are the raw materials for making ammonia and where are they obtained?
Nitrogen - from the air
Hydrogen - Natural gas / other sources
What is the process for making ammonia called?
The Haber Process
What is a reversible reaction?
The reaction between nitrogen and hydrogen can proceed in both directions - ammonia breaks down again into nitrogen and hydrogen.
What conditions are needed for the Haber process?
High temperature (450°C)
High pressure (200 atmospheres)
Iron catalyst
What is equilibrium?
The point in reversible reaction where the forward and reverse rates of a reaction are equal and so the amount of reactants and products stay the same.
How does increasing pressure affect a reaction?
The reaction creating the product with the least amount of molecules (big numbers) is favoured.
How does changing temperature affect a reaction?
Increasing temperature favours the endothermic reaction.
Decreasing temperature favours the exothermic reaction.
Give an advantage and disadvantage of increasing pressure in the Haber process.
The equilibrium yield of ammonia is increased if the pressure is increased.
Increasing pressure is costly for companies as it requires a lot of energy and strong equipment.
Give an advantage and disadvantage of decreasing temperature in the Haber process.
The equilibrium yield of ammonia is increased if the temperature is decreased.
Decreasing temperature means the particles have less energy and so the rate of reaction will decrease.
