The rearrangement of methyl isonitrile (CH3NC) to acetonitrile (CH3CN) is a first-order reaction and has a rate constant of 5.11x10^-5 s^-1 at 472 K. If the initial concentration of CH3NC is 3.50×10-2 M.
(3)How many minutes does it take for 20% of the CH3NC to react?