Cresterea masei vasului reprezinta masa de etena, singura care reactioneaza cu apa de brom, metanul reactionand cu bromul in conditii fotochimice, diferite de cele prezentate de problema
28mg............................188mg
CH2=CH2 + Br2 -> Br-CH2-CH2-Br
11,2mg..........................x=?
x=11,2*188/28=75,2mg 1,2-dibromoetan
n=m/M=V/Vm => V=m*Vm/M=11,2*22,4/28=8,96cm³ etena
Vmetan=20-8,96=11,04cm³ metan
%metan=Vmetan*100/Vamestec=11,04*100/20=55,2%
%etena=Vetena*100/Vamestec=8,96*100/20=44,8%