For irreversible first-order reactions in series, CR0 = CS0 = 0, when will the formation rate of S reach the maximum if k1 = 1 h-1 and k2 = 10 h-1.

ki 2. For irreversible first-order reactions in series, ARS, Cro= Cso= 0, when will the formation rate of S reach the maximum if k, = 1 h' and k2 = 10 h