Steam reforming of methane ( CH₄ ) produces "synthesis gas," a mixture of carbon monoxide gas and hydrogen gas, which is the starting point for many important industrial chemical syntheses. An industrial chemist studying this reaction fills a 125 L tank with 40 mol of methane gas and 8.4 mol of water vapor, and when the mixture has come to equilibrium measures the amount of hydrogen gas to be 10 mol. Calculate the concentration equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round your answer to 2 significant digits.