CHEMISTRYThe effective radius, a, of a random coil is related to its radius of gyration, $R_{g},$ by $a=\gamma R_{g},$ with $\gamma=0.85.$ Deduce an expression for the osmotic virial coefficient, B, in terms of the number of chain units for (a) a freely jointed chain, (b) a chain with tetrahedral bond angles. Evaluate B for l = 154 pm and N = 4000. Estimate B for a randomly coiled polyethylene chain of arbitrary molar mass, M, and evaluate it for $M=56\ \mathrm{kg}\ \mathrm{mol}^{-1}.$