Question

With the increasing molecular mass of a liquid the viscosity

Answer 1

Strictly speaking the viscosity average molecular weight will be the same - the molecular weight distibution not necessarily. For this you have to make GPC. This can be important if you try to compare PMMA samples of different origin, prepared by various techniques, with different tacticity etc. If, however, you compare samples prepared by th same polymerization technique and you want to study the effect of polmyerization parameters on the average molecular wight, you can rely on this simple technique.