-[(-CH2-CH=CH-CH2-)x-(CH2-(CN)CH-)y-]n-
x/y = 2/1 x = 2y
ptr. y = 1 x = 2 cauciuc : -[(-CH2-CH=CH-CH2-)2-CH2-CH(CN)-]n
%N = 14·100/161 = 8,695%
% butadiena = 2·100/3 = 66,66% (procent molar) = 108·100/161 = 67,08%(procent masic)
%acrilonitril = 33,33% (procent molar) = 32,92% (procente de masa)