Le Chatelier's Principle states that when a system is subject to stress, the equilibrium will shift in such a way as to minimise the effect of that stress.

Consider the reaction between nitrogen and hydrogen to form ammonia:
N_2(g) + 3H_2(g) <-> 3NH_2(g) ΔH = -92.4 kJ mol^-1

What will be the effects of the following changes made to this system?
1. Increase the concentration of nitrogen [N_2(g)]: Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

2. What happens to the concentration of hydrogen when the pressure on the system is decreased? Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

3. Increase the temperature of the system: Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

4. What happens to the concentration of hydrogen if nitrogen is removed? Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

5. Decrease the pressure on the system: Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

6. What happens to the concentration of ammonia if the temperature is increased? Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

7. What happens to the concentration of nitrogen if more hydrogen is added? Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right

8. What happens to the concentration of nitrogen if the volume of the container is made smaller? Concentration of hydrogen decreasesConcentration of hydrogen increasesConcentration of nitrogen decreasesConcentration of nitrogen increasesLess ammonia [N_2(g)] is formedMore ammonia [NH_3(g)] is formedThe equilibrium shifts to the leftThe equilibrium shifts to the right