Urgent va rog muuuult la chimie cine se pricepe

avem formula CnH2n+1Br
miu = 14n+81 g/mol
100% ........................... 5,69% H
14n+81 g ................. 2n+1 g H
=> n = 63/21 = 3
=> C3H7Br
H3C-CH2-CH2-Br
H3C-CH-Br
CH3