Studied by 1 person
Looks like no one added any tags here yet for you.
what is the Haber process?
-manufactures ammonia from nitrogen and hydrogen
reaction equation
energy change of the forward reaction
-93kJ/mol -exothermic
usual conditions chosen
-pressure of 200 atmospheres/ 20 MPa -a temperature of 450 degrees Celsius -an iron catalyst
yield of ammonia in chosen conditions
-about 30%
why is the pressure chosen?
-increased pressure moves to right -however, cannot increase the pressure too much as it would be hazardous and expensive -increased yield would not justify the additional costs
why is the temperature chosen?
-the forward reaction is exothermic -if the temperature is increased, the equilibrium moves to the left, so low temperatures produced a higher yield -the temperature is a compromise: low enough to achieve reasonable yield, but high enough to achieve a reasonable rate of reaction -also, the iron catalyst works best above 400 degrees Celsius
what other conditions are chosen?
-the mixture of gases leaving the reaction is cooled so that ammonia is a liquid -this allows the ammonia to be removed, and unreacted nitrogen and hydrogen to be recycled -this improves the overall yield to about 97%
Note 
Flashcard (59)