a) 2CH4 => C2H2 + 3H2
C2H2 + HCN => C2H3CN
nC2H3CN ----> -[-C2H3CN-]-n
b) n CH4 = V/Vm = 2240/22,4 = 100 moli
n pur = 0,8×100 = 80 moli
2 moli CH4.........1 mol C2H2
80 moli.............x = 40 moli
n C2H2 folosita = 3/4×40 = 30 moli
n C2H2 = n C2H3CN = 30 moli
m polimer = 30×53 = 1590g