Question

Question text
Given the following exothermic, equilibrium reaction:

3 H2(g) + N2(g) <--> 2NH3(g)

Using Le Chatelier's Principle, which of the following changes would shift the equilibrium toward more production of NH3?
Select one:
a. Adding a catalyst
b. Adding heat
c. Increasing the volume of the container
d. Removing NH3

Answer 1

Le Chatelier's Principle tells us that if we do something to affect the equilibrium of a reaction, it will try to undo what we did to it.

I would rewrite the equation as
3H2(g) + N2(g) ==> 2NH3(g) + heat

Adding a catalyst NEVER changes the equilibrium although it changes the SPEED of the reaction.

Adding heat. Since the reaction produces heat, it will try to reduce the heat and the only way it can do that is to move to the left because that USES heat.

Increasing the volume means the pressure is decreased. Increasing P move the equilibrium to the side with fewer mols; therefore, decreasing P moves to the side with more moles which means it goes to the left.

What about removing NH3? If you take NH3 AWAY, the reaction will try to produce MORE NH3.