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2 marksAmmonia

CAPE Chemistry Unit 2 · May/June 2021 · Paper 2 · Question 3(a)(ii)

This module covers industry and the environment. Figure 1 shows The Haber-Bosch synthesis of ammonia from its elements. The equation for the synthesis is N₂(g) + 3H₂(g) ⇌ 2NH₃(g) (∆Hᵣ = -92.38 kJ).

Using Le Chatelier's principle, explain the effect of temperature on the direction of equilibrium for the ammonia formation.

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Other parts of this question

  1. 3(a)(i)State ONE reason why a catalyst is needed in this reaction.[1 mark]
  2. 3(a)(iii)State whether the temperatures used in the Haber-Bosch synthesis favour the formation of high yields of ammonia.[1 mark]
  3. 3(a)(iv)Comment on the statement “High pressure conditions favour the formation of ammonia in high yields."[2 marks]
  4. 3(a)(v)With reference to Figure 1 on page 13, state TWO possible design limitations that could lead to reduced product yield.[2 marks]
  5. 3(a)(vi)Write the Kₚ expression for the Haber–Bosch process.[1 mark]
  6. 3(a)(vii)State the impact of the catalyst on the Kₚ of the reaction.[1 mark]
  7. 3(b)(i)Complete statement (i).[1 mark]
  8. 3(b)(ii)Complete statement (ii).[1 mark]
  9. 3(b)(iii)Complete statement (iii).[2 marks]
  10. 3(b)(iv)Complete statement (iv).[2 marks]
  11. 3(b)(v)Comment on the statement "The production of ammonia under standard atmospheric conditions would prove to be more efficient in the presence of a catalyst than…[2 marks]
  12. 3(b)(vi)Identify another feature in the design that makes it 'green', apart from the use of a catalyst in the existing Haber-Bosch process.[1 mark]
  13. 3(c)(i)Write ONE equation that represents a step in this process.[2 marks]
  14. 3(c)(ii)Write TWO statements that support the idea that ethanol is a green resource.[1 mark]
  15. 3(c)(iii)State TWO factors that would preclude countries in the Caribbean from considering sugar beets as a viable source crop for ethanol production.[2 marks]
  16. 3(c)(iv)Describe the role of ethanol in this process.[2 marks]
  17. 3(c)(v)Match EACH formulation using the letters A, B or C with the appropriate set of characteristics that best describes it.[3 marks]

More practice: the rest of this paper · more Ammonia questions · all CAPE Chemistry Unit 2 past papers