Question

A mixture of hydrogen and nitrogen, which produces ammonia (NH3) in a reaction vessel, is allowed to reach equilibrium at a given temperature. The equilibrium mixture of gases contained 0.254 M NH3, 1.85 M N2, and 9.26 M H2. Calculate the equilibrium constant, Kc at this temperature.

Answer 1

Answer: $1.10\times 10^3$

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_{eq}$

The given balanced equilibrium reaction is,

                            $3H_2(g)+N_2(g)\rightleftharpoons 2NH_3(g)$

At eqm. conc.     1.85 M         9.26M         0.254M

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[NH_3]^2}{[N_2][H_2]^3}$

Now put all the given values in this expression, we get :

$K_c=\frac{(0.254)^2}{(9.26)\times (1.85)^3}$

$K_c=1.10\times 10^3$

Thus the value of the equilibrium constant is $1.10\times 10^3$