A crosslinked copolymer consists of 52 wt% ethylene (C2H4) repeat units and 48 wt% propylene (C3H6) repeat units. Determine the fraction of (a) ethylene and (b) propylene repeat units

The fraction of (a) ethylene to (b) propylene repeat units is 163 to 100

Explanation:

Suppose that we get 100 g of the given co-polymer sample, in that sample it consists of 52 g of (a) and 48 g of (b), the MW of (a) is 28 and (b) is 42.

Then we calculate the mole of each polymer in the sample

n (a) = 52/28 = 1.86

n (b) = 48/42 = 1.14

Hence, the fraction of (a) to (b) is n (a) / n (b) = 1.86/1.14 = 163/100