9.4 A 0.16 mol dm solution (3.50 cm) of s-butyllithium in toluene was added to a solution of sty- rene (8.40 g) in toluene (200 cm). After complete conversion of the styrene, isoprene (28.00 g) was added. When the isoprene had completely polymerized, the reaction was completed by addi- tion of a 0.10 mol cm solution (2.80 cm) of dichloromethane in toluene. (a) Write down the reactions occurring in each stage of this reaction sequence and show the structure of the final polymer. (b) Evaluate the relevant degrees of polymerization and the corresponding molar masses for the final polymer.