How Do You Calculate the Fraction of Ethylene in a Copolymer?

[][nstigator]

Heres a question I am stuck with

Crosslinked polymers consisting of 62 wt% ethylene and 38 wt% propylene may have elastic properties similar those for natural rubber. For a copolymer of this composition, determine the fraction of the ethylene mer.

Express your answer with three decimal points.


I honestly am lost with how to do this question...

What I did was...

Found the weight of ethylene (28.052) and the weight of propylene (42.078)...then multipled by the percentages and got...

28.052*0.62 = 17.39
42.078*0.38 = 15.98

then..

fraction = 17.39/(15.98+17.39)

I doubt this is right...any help would be much appreciated.

Thanks in advance!

 

[][nstigator]

Sorry I think I posted this in the wrong section.

My apologies