n1 moli CH3-CH2-CH3 = CH4 + C2H4
n2 moli C3H8 = C3H6 + H2 n1 + n2 = n
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amestec final : n1 moli CH4 + n1moli C2H4 + n2moliC3H6 + n2 moli H2
n final = 2n1 + 2n2 = 2(n1+n2) = 2n
mf = mi = 44n
28n1·100/(44n) = 30 η = n1·100/n = 30·44/28 = 41,14%