The following reactions take place in series. The first is Oth order. The second is 1st order. Reaction 1: A D Reaction 2: D-U Rate: r = k Rate: 1 = k CD with k = 2 with k = 0.01 Initially, there is only A, with CA0 = 250 mol/m and the relevant time-scale for analysis is in minutes. a.) What are the units of k and k? b.) What are the concentrations of A and D as functions of time? c.) At what time will the reaction stop? And what are the concentrations of A and D at that time? d.) What is the overall yield of D and overall selectivity (of D to U) at this time?