For the conversion of methyl isonitrile to acetonitrile in the gas phase at 250 oC CH3NC CH3CN the following data have been obtained: [CH3NC], M 0.119 7.59E-2 4.84E-2 3.08E-2 time, s 0 150 300 450 The average rate of disappearance of CH3NC over the time period from t = 0 s to t = 150 s is