formula generala a alchinei : CnH2n-2
Alchina este simetrica, deci va fi de forma R-C≡ C-R
Produsul diclorurat obtinut prin aditie are masa molara M=14n-2+71 , g/mol
CnH2n-2 +Cl2--> CnH2n-2Cl2
deduc n
100g produs...........56,8clor
14n+69 g...................71g clor
7100= 56,8(14n+69)----> n=4----> 2 butina--
CH3-C≡C-CH3+Cl2---> CH3-CCL=CCL-CH3 2,3,DICLORO 2 BUTENA
Acest produs are 2 izomeri geometrici: cis si trans
CH3 CH3 Cl CH3
C=C C=C
Cl Cl CH3 Cl