Consider the following reaction involving bromophemol blue (BPB) and OH- : HBPB(aq) + OH-(aq) = BPB-(aq) + H2O(l). The concentration of BPB can be monitored by following the absorption of this species and using Beer-Lambert law. In this law, the absorption A and concentration are linearly relate.
a) Express the reaction rate in terms of the change in absorbance as a function of time.
b) Let A0 be the absorbance due to HBPB at the beginning of the reaction. Assuming that the reaction is first order with respect to both reactants, how is the absorbance of HBPB expected to change with time?
c) Given your answer in part (b), what plot would you construct to determine the rate constant for the reaction?