Analysis of a reaction mixture showed that it had the composition 0.411 mol/L N2, 0.535 mol/L H2, and 0.118 mol/L NH3 at 800 K, at which temperature Kc = 0.278 for N2(g) + 3 H2(g) ⇀↽ 2 NH3(g). Calculate the reaction quotient Qc .