The following equilibrium exists in a closed container: N2(g) + O2(g) = 2NO(g), ΔH = +181 kJ/mol. Which of the following perturbations would favor the formation of NO(g)? (practice MCAT question from The Princeton Review MCAT Science Workbook, 2009 edition)

Question

The following equilibrium exists in a closed container: N2(g) + O2(g) = 2NO(g), ΔH = +181 kJ/mol. Which of the following perturbations would favor the formation of NO(g)? (practice MCAT question from The Princeton Review MCAT Science Workbook, 2009 edition)
		
increasing the pressure
		
decreasing the pressure
		
Increasing the temperature
		
decreasing the temperature

DrBob222 · Answer

N2 + O2 + heat ==> 2NO
You go through the same reasoning as the last problem we did. You didn't have pressure in that one but the rule on pressure is an increase in P shifts the equilibrium to the side with fewer mols gas. Since you have 2 mols on the left and 2 mols on the right and increase or decrease in P will not affect the equilibrium. You want to increase NO so how can you do it.

danny · Answer

increase the temperature ?

DrBob222 · Answer

sure. Since it is an endothermic reaction, increasing T will shift it to the right and that will produce more NO