Question

Equilibrium constant, K_c for the reaction 

\[\ce{N2 (g) + 3H2 (g) ⇌ 2NH3 (g)}\] at 500 K is 0.061.

At a particular time, the analysis shows that composition of the reaction mixture is 3.0 mol L^–1 N₂, 2.0 mol L^–1 H₂ and 0.5 mol L^–1 NH₃. Is the reaction at equilibrium? If not in which direction does the reaction tend to proceed to reach equilibrium?

Answer 1

The given reaction is:

	N2(g)	+	3H2(g)	↔	2NH3(g)
At a particular time	3.0 mol L-1		2.0 mol L-1		0.5 mol L-1

Now, we know that,

`"Q"_"C" = ["NH"_3]^2/(["N"_2]["H"_2]^3)`

` =(0.5)^2/((3.0)(2.0)^3)`

= 0.0104 

it is given that `"K"_"C"` = 0.061

Since `"Q"_"C" != "K"_"C"`, the reaction is not at equilibrium.

Since `"Q"_"C" < "K"_"C"`, the reaction will proceed in the forward direction to reach equilibrium.