Question

The chemical reaction N₂(g) + 3 H₂(g) ---> 2 NH₃(g) energy, has stresses that are applied. each stress causes a shift in the equilibrium. which stress on the system will decrease the production of NH3(g)?

(A) increasing the concentration of N₂(g)
(B) increasing the pressure on the system
(C) decreasing the concentration of H₂(g)
(D) decreasing the temperature on the system

Answer 1

Decreasing the concentration of
`H_2(g)` will decrease the production of
`NH_3`(g). Option C is the right choice.

The reaction produces fewer moles of gas on the product side than the reactant side. Therefore, increasing the pressure will favor the forward reaction (fewer gas molecules) and increase
`NH_3` production, eliminating (B) as an option.

Decreasing the temperature will favor the exothermic reaction (forward reaction) and increase
`NH_3` production, eliminating (D) as an option.

Increasing the concentration of
`N_2` will shift the equilibrium to the right according to Le Chatelier's principle, increasing
`NH_3` production, eliminating (A) as an option.

Therefore, the only stress that will decrease
`NH_3` production is (C) decreasing the concentration of
`H_2(g)`, as it shifts the equilibrium to the left, favoring the reactants.

Option C is the right choice.