M.molec. = d(N2) x M.molec.(N2 = 2 x 28 = 56 g/mol
CnH2n, M.molec. alchena = 14n
=> 14n = 56 => n = 4 => C4H8 = butena
1-butena => 1-butanol
cis-2-butena => 2-butanol
trans-2-butena => 2-butanol
2-metilpropena => 2-metil-2-propanol
=> 3 alcooli izomeri => B.