A reaction vessel contains NH3, N2, and H2 at equilibrium at a certain temperature. The equilibrium concentrations are [N2] = 0.71 M, [H2] = 1.71 M, and [NH3] = 0.90 M. Calculate the equilibrium constant, Kc, if the reaction is represented as

(

1

2

)N2(g) + (

3

2

)H2(g) NH3(g)