Question

The Haber's process for the manufacture of ammonia is usually carried out at about 500⁰C. If a temperature of about 250⁰C was used instead of 500⁰C -

• A. ammonia would not be formed at all
• B. the percentage of ammonia in the equilibrium mixture would be too low
• C. a catalyst would be of no use at all at this temperature
• D. the rate of formation of ammonia would be too slow

Answer 1

The correct option is D the rate of formation of ammonia would be too slow

The minimum temperature at which the combination of N₂ and H₂ occurs at measurable rate is 500⁰C in Haber's process. No doubt if temperature is raised up, above 500⁰C, it will favour backward reaction , because the reaction is exothermic.