Figure 6 shows a flow diagram for the Haber process - AQA - GCSE Chemistry - Question 6 - 2016 - Paper 3
Question 6
Figure 6 shows a flow diagram for the Haber process.
Figure 6
Nitrogen gas
Hydrogen gas
Reactor containing iron
Mixture of gases
(nitrogen, hydrogen and ... show full transcript
Worked Solution & Example Answer:Figure 6 shows a flow diagram for the Haber process - AQA - GCSE Chemistry - Question 6 - 2016 - Paper 3
Step 1
6 (a) (i) Hydrogen gas is obtained from methane. Name one source of methane.
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Answer
One source of methane is natural gas.
Step 2
6 (a) (ii) Air is the source used to produce nitrogen for the Haber process. Suggest why air must not get into the reactor.
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Answer
Air contains oxygen, which would react with and oxidize the hydrogen in the reactor. This reaction would reduce the amount of hydrogen available for ammonia production and potentially damage the iron catalyst.
Step 3
6 (a) (iii) Describe what happens to the mixture of gases from the reactor.
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The mixture of gases is cooled, allowing ammonia to condense and separate. The ammonia can then be collected, while the unreacted nitrogen and hydrogen gases are recycled back into the reactor.
Step 4
6 (b) (i) Use Figure 7 to suggest the conditions that produce the greatest yield of ammonia.
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The conditions that produce the greatest yield of ammonia are at 200 °C and 1000 atmospheres.
Step 5
6 (b) (ii) Use Figure 7 to suggest and explain why the conditions used to produce ammonia in the Haber process are a temperature of 450 °C and a pressure of 200 atmospheres.
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The reaction is reversible and exothermic, meaning that lower temperatures would favor the formation of ammonia, but a very low temperature would slow down the reaction rate. A temperature of 450 °C is a compromise, allowing a reasonable yield while maintaining a faster reaction rate. Additionally, higher pressures increase the yield of ammonia as they shift the equilibrium towards the product side, but extremely high pressures can be costly. Thus, a pressure of 200 atmospheres is a balanced choice.
