Consider the following reaction at equilibrium:

4NH3(g) + 5O2(g) ↔ 4NO(g) + 6H2O(g)
In what direction will the following changes force the reaction?
a) Addition of O2
b) Reduction of the amount of water vapour
c) Increase in the pressure
d) Decrease in the volume
e) If this reaction is exothermic, how does an increase in the temperature influence the
reaction?

1 answer

In every day language, Le Chatelier's Principle says that an equation in equilibrium will try to undo what we do to it.

Adding O2 means it will shift so as to use up O2. So it goes to the right.
Reducing H2O means it will try to make more H2O so it will shift to the right.

etc.