3H2 (g) + N2 (g) 2NH3 (g) This reaction has a equilibrium constant of 4.51x10-5 at 450 °C and initially contains 5.4 atm NH3, 2.7 atm N2, and 1.4 atm H2. In which direction will the reaction go in order to attain equilibrium? A) Stay the same B) Toward the products C) Toward the reactants D) Changes the equilibrium

C) Toward the reactants.

Explanation:

Based in the reaction:

3H₂ (g) + N₂ (g) → 2NH₃ (g)

Equilibrium constant, K, is:

K = 4.51x10⁻⁵ = [NH₃]² / [H₂]³[N₂]

Where gas concentrations are equilibrium concentrations.

Reaction quotient, Q, is:

Q = [NH₃]² / [H₂]³[N₂]

But concentrations not necessary are in equilibrium

If Q = Ksp, the reaction is in equilibrium, if Q > Ksp, the reaction goes toward reactants and if Q < Ksp, the reaction goes toward products.

Replacing with values of the problem:

Q = [5.4]² / [1.4]³[2.7] = 3.936

As Q > Ksp, the reaction goes toward reactants.

Right answer is:

C) Toward the reactants.