Nitric oxide, NO, is an intermediate in the production of nitric acid. It is produced commercially by the controlled oxidation of ammonia. Suppose you are considering how to increase the amount of NO produced each day in the equilibrium 4 NH₃(g) + 5 O₂(g) ⇌ 4 NO(g) + 6 H₂O(g). Predict the effect on each equilibrium concentration of 

(a) The removal of NO; 

(b) The addition of NH₃; 

(c) The addition of H₂O.

ANTICIPATE Because the removal of a product and the addition of a reactant cause a shift toward the formation of product, you should expect (a) and (b) to shift the equilibrium toward products, whereas (c) will shift the reaction toward reactants.

PLAN Consider how each change will affect the value of Q and what change is then needed to re-establish equilibrium.