At this temperature, the methanol vaporizes and decomposes according to the reaction, a quantity of liquid methanol, CH3OH, is introduced into a rigid 3.00-L vessel, the vessel is sealed, and the temperature is raised to 500K.
CH3OH (g) ↔ CO(g) + 2 H2(g),Kc = 6.90x10-2.
If the concentration of H2 in the equilibrium mixture is 0.426 M, explain what mass of methanol was initially introduced into the vessel?