Equilibrium

Question

What would happen if O2 were removed from the following system at equilibrium at 25 degrees C?

 

2NO2(g) <--> 2NO(G) + O2(G)      Kc=7.4*10^-1

a. NO2 and NO concentrations would increase

b. NO2 and NO concentrations would decrease

c. NO2 concentration would increase, NO concentration would decrease

d. NO2 concentration would decrease, NO concentration would increase

e. none of above

 

I marked a, but also debating about d

Answer 1

Le Chatelier's Principle: When a system at equilibrium is perturbed, the system will respond in a way to try to off set that change.

 

2NO₂(g) <==> 2NO(g) + 2O₂(g)

If you remove O₂ (a product), that will tend to pull the reaction to the right.  Thus, [NO₂] would decrease, and the [NO] would increase.  So, answer should be (d).