The gas phase decomposition of dimethyl ether at 500 °C CH3OCH3(g) CH4(g) + H2(g) + CO(g) is first order in CH3OCH3 with a rate constant of 4.00×10-4 s-1. If the initial concentration of CH3OCH3 is 3.48×10-2 M, the concentration of CH3OCH3 will be M after 5158 s have passed.