Given the equation representing a system at equilibrium N2(g)

Explanation:

The complete question is:

Given the equation representing a system at equilibrium:

what changes occur when the temperature of this system is decreased?

Modifying the temperature of a system in equilibrium changes the equilibrium constant and the equilibrium position (concentrations) of the system.

When the temperature is decreased, following LeChatelier's principle that the system will react in a way that seeks to counteract the disturbance, the reaction will shift toward the reaction that produces more heat energy to compensate the temperature decrease.

Thus, decreasing the temperature of the system will favor the forward reaction, more N₂(g)  and H₂(g) will be consumed and more NH₃(g) and energy will be produced. Hence, the equilibrium will shift rightward.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)