Question

72) O proba cu masa de 20,56 g dintr-un amestec de 1 hexena si n-hexan decoloreaza total in absenta luminii si la rece 128 g de solutie de br2 in ccl4 de concentratie 5%.Raportul molar n hexan : 1 hexena in proba analizata este :c) 5:1

Answer 1

Doar hexena reactioneaza cu apa de brom
md=c*ms/100=5*128/100=6,4g
84g.................................160g
CH2=CH-(CH2)3-CH3 + Br2 -> CH2(Br)-CH(Br)-(CH2)3-CH3
x=?..................................6,4g
x=6,4*84/160=3,36g hexena => 17,2g hexan
n hexena=3,36/84=0,04moli
n hexan=17,2/86=0,2moli
nhexan:nhexena=0,2:0,04=5:1