i. The rate of migration of a property is measured by its flux J. Find general formulations for the flux of matter (diffusion), energy (thermal conduction) and momentum (viscosity) and describe what they have in common. iv. The relationship between intrinsic viscosity [] and molecular weight M (in g mol-1) of a polyisobutylene solution can be described with the following formula: [] = 3.60 104 M0.64 . (12) What is the molecular weight of a polyisobutylene fraction that gives a solution with intrinsic viscosity of 1.80 dL g-1?