For polymerization of styrene in tetrahydrofuran using sodium naphthlide as initiator, the rate coefficient for propagation is 550 dm3 mol-1 s -1 . If the initial mass concentration of styrene is 156 g/dm3 and that of sodium naphthalide is 3.02 x 10-2 g/dm3 , calculate the initial rate of polymerization, reaction time, polydispersity, the number average for 90% conversion of the styrene,