CnH2n-1Cl
M g ...... 35.5 g Cl
100g.....46.4 g Cl
M= 35.5 x100/46.4=76.5
76.5 - 35.5 (m Cl) = 41
12n + 2n-1=41
14n - 1= 41
14 n= 40
n=2.85 = 3
C3H5Cl
daca facem calculul pt M = 12 x 3 + 5x1 + 35.5 =76.5 g/mol
compusul poate fi 1-cloropropena, 2-cloropropena sau 3-cloropropena