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

To determine which change would shift the equilibrium towards more production of NH3, we need to apply Le Chatelier's Principle. Le Chatelier's Principle states that when a system at equilibrium is subjected to a change, it will adjust to counteract the change.

In this exothermic, equilibrium reaction:
3 H2(g) + N2(g) <--> 2NH3(g)

a. Adding a catalyst: A catalyst does not shift the equilibrium position of a reaction. It speeds up the rate of both the forward and reverse reactions equally, allowing the system to reach equilibrium faster, but it does not affect the position of the equilibrium.

b. Adding heat: Since the reaction is exothermic, adding heat to the system would shift the equilibrium in the reverse direction to absorb the excess heat. This would result in a decrease in the production of NH3.

c. Increasing the volume of the container: Increasing the volume of a gaseous system at equilibrium would cause the system to shift in the direction that produces fewer moles of gas. In this case, the forward reaction produces 2 moles of NH3 while the reverse reaction only produces 1 mole of gas (N2). Therefore, increasing the volume would shift the equilibrium towards the forward reaction, leading to more production of NH3.

d. Removing NH3: According to Le Chatelier's Principle, if one of the products is removed, the equilibrium will shift in the forward direction to replace the lost molecules. Therefore, removing NH3 would shift the equilibrium towards more production of NH3.

Based on these explanations, the answer that would shift the equilibrium toward more production of NH3 is:

c. Increasing the volume of the container

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.