大家有没有听过这两个词呀? just give some background average molecular weight = sigma[w(i)*mw(i)]/sigma[w(i)], i = 1 to n where "w" is the weight, and mw is the molecular weight (molar mass). n is the number of the species in the mixture. sigma means summation. if w(i) = viscosity (i), it is viscosity average. but the most frequently used are (mole) number average and mass average.查看更多