In order to both shift the equilibrium and increase the yield of ammonia, we should?

For the reaction system N2(g) + 3H2(g) ⇌ 2NH3(g) at equilibrium, ΔH is -92 kJ. In order to both shift the equilibrium and increase the yield of ammonia, we should

1. increase the temperature

2. decrease the temperature

3. increase the pressure

4. decrease the pressure

A) 1 only
B) 2 only
C) 1 and 3 only
D) 2 and 3 only
E) 1 and 4 only

1 Answer
Apr 28, 2018

This is a very poor question....the answer they want is probably #D#...

Explanation:

The actual answer is probably #C#...

We gots #1/2N_2(g) + 3/2H_2(g) rightleftharpoons NH_3(g)+Delta#

The reactants exert more pressure than the products...and so increasing the pressure should drive the equilibrium to the right. Increasing the temperature should drive the equilibrium to the left as we face the page (i.e. we supply #Delta# and the PRODUCT is disfavoured).

In actual fact, if this reaction is run at lower temperatures, the reaction proceeds at an unacceptably LOW rate. The reaction is run at more elevated temperatures to enhance rate and turnover.

This is one to talk over with your chem prof.