A mixture of 1.57 mol of N2, 1.92 mol of H2 and 8.13 mol of NH3 is introduced into a 20 L reaction vessel at 500 K. At this temperature, the equilibrium constant, Kc for the reaction N2 (g) + 3H2 (g)⇌2NH3 (g) is 1.7 × 102. Is the reaction mixture at equilibrium? If not, what is the direction of the net reaction?
Concentration of substance,
[substance] =
Thus, concentrations of given substances are,
[N2] = 1.57/20 mol L-1
[H2] = 1.92/20 mol L-1
[NH3] = 8.13/20 mol L-1
For a chemical change,
aA + bB ⇌ cC + dD
Reaction quotient Qc for the reaction is,
Qc =
Where [substance] is concentration of substance at a particular time.
For given reaction
N2 (g) + 3H2 (g)⇌2NH3 (g)
Reaction quotient is,
Qc = =
Qc >Kc . Therefore, the reaction proceeds in reverse direction in order to attain equilibrium. (Equilibrium constant is reaction coefficient at equilibrium state)