alcan avem CaH2a+2
a = n2-2
2a+2 = 3n+7
=> 2n2-4+2 = 3n+7
=> 2n2-3n-9 =0 => rezolvam ec. de grad. II
=> n=3
=> C7H16, heptan
A) - A
B) - A
C-C-C-C-C-C-C 1x
C-C-C-C-C-C
C 1x
C-C-C-C-C-C
C 2x
C-C-C-C-C
C C 2x
C
C-C-C-C-C
C 1x
C-C-C-C-C
C-C 1x
C
C-C-C-C-C
C 1x
C
C-C-C-C-C
C 1x
C
C-C-C-C
C C 1x
C)- A
D)-F
E)-F
F)-A