Calculate the required concentration of benzoyl peroxide (in the unit of g/cm3 ) for a polystyrene (PS) polymerization in order to obtain PS number-average molecular weight of 105g/mol, and obtain the rate of polymerization (in the unit of mole m3s1 ). The known parameters are (1) the efficiency of initiator dissociation is 80%,(2) the rate constants of dissociation, propagation and termination are 2106s1,0.35m3mol1s1, and 4104m3mol1s1, respectively, and (3) the densities of styrene is 0.85g/cm3. Estimate how long it takes to have 90% of styrene being consumed (assuming steady state of radical)? If the disproportionation and chain transfer is negligible. (Please pay extra attention to the unit conversion)