Given the following reaction:

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

If the following changes were to occur what direction shift will it have (left or right)
And what will be the reason of the shift

Changes/Stress on system:
Adding NH3
Decreasing the pressure
Adding heat
Removing N2
Increasing the pressure

To determine the direction of the shift in the given reaction, we need to consider Le Chatelier's principle. Le Chatelier's principle states that if a change or stress is applied to a system at equilibrium, the system will try to counteract or reduce the effect of that change. Let's analyze each change and its effect on the equilibrium:

1. Adding NH3: When NH3 is added, it will increase the concentration of NH3 in the reaction mixture. According to Le Chatelier's principle, the system will shift in the direction that reduces the concentration of NH3 to counteract the increase. Therefore, the reaction will shift to the left.

2. Decreasing the pressure: The decrease in pressure will cause the system to shift in the direction that reduces the total number of moles of gas. In the given reaction, there is a decrease of 3 moles of gas on the left side (3H2 + N2) and an increase of 2 moles of gas on the right side (2NH3). Thus, the reaction will shift to the right to increase the total number of moles of gas and restore the equilibrium.

3. Adding heat: The addition of heat is considered an increase in temperature. In an exothermic reaction, like the one given, an increase in temperature will favor the reverse reaction (the one that absorbs heat) to counteract the increase. Therefore, the reaction will shift to the left to absorb the added heat and restore equilibrium.

4. Removing N2: When N2 is removed, the reaction will shift in the direction that produces more N2 to compensate for the loss. In this case, it will shift to the right to produce more N2.

5. Increasing the pressure: An increase in pressure will cause the system to shift in the direction that reduces the total number of moles of gas. As mentioned earlier, there are 3 moles of gas on the left side and 2 moles of gas on the right side of the reaction. Thus, the reaction will shift to the left to decrease the total number of moles of gas and balance the pressure.

In summary, the given changes/stresses on the system will cause the reaction to shift in the following directions:
- Adding NH3: Shifts to the left
- Decreasing the pressure: Shifts to the right
- Adding heat: Shifts to the left
- Removing N2: Shifts to the right
- Increasing the pressure: Shifts to the left