A = CxHyOz
M B = 7,96·28,9 = 230g/mol
daca reactia cu Br2 = reactie de aditie : M A = 230 - 160 = 70 g/mol
mH = 6 12x + 6 + 16z = 70 12x + 16z = 64 3x + 4z = 16 ⇒
⇒ ptr. z = 1 x = 4 A = C4H6O NE = 2 ⇔ 2 duble legaturi (C=C + C=O)
C4H6O + 2H2 = C4H10O %H = 10·100/74 = 13,51%
A poate fi : CH2=CH-CH2-CH=O