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MDCAT
Chemistry
2021

Chemistry · Chemical Equilibrium

Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive practice and topic analytics.

Question

The rate of formation of ammonia is not economical at?

Options
  • A

    Low temperature

  • B

    High temperature

  • C

    Both A and B

  • D

    None of these

Explanation

While the rate of ammonia formation is slow at low temperatures, low temperatures indeed favor the formation of ammonia according to Le Chatelier's principle. However, the yield of ammonia is low at low temperatures. Therefore, the optimal temperature for ammonia synthesis is typically around 450-550°C, which provides a balance between the rate of ammonia formation and the yield of ammonia.

While the rate of ammonia formation is slow at low temperatures, it is true that low temperatures favor the formation of ammonia according to Le Chatelier's principle. However, the yield of ammonia is low at low temperatures. Therefore, the optimal temperature for ammonia synthesis is typically around 450-550°C, which provides a balance between the rate of ammonia formation and the yield of ammonia.

The rate of formation of ammonia is higher at higher temperatures, but the yield of ammonia decreases at higher temperatures. This is because the forward reaction (the formation of ammonia from nitrogen and hydrogen) is exothermic, meaning it releases heat. According to Le Chatelier's principle, increasing the temperature of the reaction will shift the equilibrium towards the side of the reaction that absorbs heat, which in this case is the reactant's side. Therefore, increasing the temperature of the reaction will increase the rate of ammonia formation, but it will also decrease the yield of ammonia. As a result, the optimal temperature for ammonia synthesis is typically around 450-550°C, which provides a balance between the rate of ammonia formation and the yield of ammonia.

While the rate of ammonia formation is slow at low temperatures, low temperatures indeed favor the formation of ammonia according to Le Chatelier's principle. However, the yield of ammonia is low at low temperatures. At high temperatures, the reaction rate increases due to higher kinetic energy and more frequent collisions.

However, because the reaction is exothermic, high temperatures shift the equilibrium position backward (towards nitrogen and hydrogen), reducing the yield of ammonia. optimum temp is used

While the rate of ammonia formation is slow at low temperatures, low temperatures indeed favor the formation of ammonia according to Le Chatelier's principle. However, the yield of ammonia is low at low temperatures. 

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Tagged under Chemistry · Chemical Equilibrium · 2021