Notez "*" inmultire si "/" impartire
CnH2n-2
dgaz=M/Mgaz =>M=dgaz*Mgaz=2.429*28=68g/mol
MN2=14*2=28g/mol
2,429=M/28--> M=68; 68=14n-2--> n-5--> pentina sau pentadiena.Pentadiena nu reactioneaza cu reactivul Tollens.2 pentina; prin oxidare da acid acetic si acid cetopropionic C5H8----->(oxidare) CH3-COOH + CH2-C=O-COOH