We’re being asked to **determine the equilibrium constant** **this reaction**:

2 NH_{3}(g) ⇌ N_{2}(g) + 3 H_{2}(g)

Recall that the ** equilibrium constant** is the ratio of the products and reactants.

We use **K _{p}** when dealing with pressure and

$\overline{){{\mathbf{K}}}_{{\mathbf{p}}}{\mathbf{=}}\frac{{\mathbf{P}}_{\mathbf{products}}}{{\mathbf{P}}_{\mathbf{reactants}}}}$ $\overline{){{\mathbf{K}}}_{{\mathbf{c}}}{\mathbf{=}}\frac{\mathbf{\left[}\mathbf{products}\mathbf{\right]}}{\mathbf{\left[}\mathbf{reactants}\mathbf{\right]}}}$

*Note that solid and liquid compounds are ignored in the equilibrium expression.*

Given the reaction

2NH_{3}(g) ⇌ N_{2}(g) + 3H_{2}(g)

At equilibrium, it was found that the concentration of H_{2} was 0.0591 M, the concentration of N_{2} was 0.0197 M, and the concentration of NH_{3} was 0.441 M. What is K_{c} for this equilibrium?

A) 3.97 × 10^{–3}

B) 1.58 × 10^{–5}

C) 2.10 × 10^{–5}

D) 2.24 × 10^{–1}

E) 2.65 × 10^{–3}

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Equilibrium Expressions concept. If you need more Equilibrium Expressions practice, you can also practice Equilibrium Expressions practice problems.