-formula generala a alchinelor CnH2n-2 cu masa molara ,M= 12n+2n-2 g/mol
in 14n -2 g alchina..........12n gC
100g 87,8
1200n= 1229n-175,6---> n=6 hexina , C6H10
CnH2n-2 + 2H2---> CnH2n+2 , alcan cu M= 12n +2n+2 g/mol
14n+2 g alcan........2n+2 gH
100g......................20
200n+200= 280n+40=====> n=2 -> etina , C2H2