An equilibrium mixture, at 529°C in a 1208-mL container, involving the chemical system
N2(g) + 3H2(g) == 2NH3(g)
is found to contain 3.62 g of N2, 0.773 g of H2, and 0.498 g of NH3. Calculate the equilibrium constant (Keq expressed in terms of the molar concentrations) at the given temperature.