n=nr de moli
n=0.2=V/22.4=>V=0.2*22.4=4.48dm3 Hc
1dm3 Hc............2,5 g
4.48 dm3 Hc......x
x=11.2g
44g CO2......12g C
35.2g CO2.....m g C
m=9,6 g c
mHc= mC+mH2=>mH2=11,2-9.6=1,6 g h2
11,2 g Hc......9.6g C....1,6g H2
100g Hc.......%C.......%H
=> %C=85,7 / : 12=7,12 / : 7,12=1
%H=14,28/ : 1=14,28/ :7,12=2
=> C1H2 => (CH2)x cu M`=14
contine o legatura pi=> o alchena sau cicloalcan
1L.....2,5 g Hc
22,4......M => M=56
x=M/M`=56/14=4 => C4H8
C=C-C-C