Question

Prin hidrogenarea naftalinei cu H2 in prezenta de Ni se obtine un amestec de tetralina si decalina ce contine 10,1123% H .Procentul de naftalina
transformata in decalina este ...

Answer 1

Tetralina are formula moleculara C10H12
Decalina are formula moleculara C10H18
masa hidrogen = 12x+18y * 100
%H=masa hidrogen/masa amestec * 100
10.1123=12x+18y/132x+138y * 100
1200x+1800y=1334.82x+1395.49y=>404.5y=134.82x=>y/x=0.333=>x=3 moli tetralina si y = 1 mol decalina
%C10H18 = n C10H18/n amestec*100 = 1/4 * 100 = 25%

Answer 2

C10H8 + 2H2 ---Ni---> C10H12 + 3H2 ---Ni---> C10H18
MC10H12=10AC+12AH=10×12+12×1=132g/mol
MC10H18=10AC+18AH=12×10+18×1=138g/mol
m hidrogen amestec = 12x + 18y
M amestec = 132x+138y
132x+138y.....................12x+18y
100..................................10.1123
(132x+138y)10.1123=1200x+1800y
1334.8236x+1395.4974=1200x+1800y
134.8236x=404.5026y
x/y=404.5026y/134.8236=>x=3 moli C10H12
134.8236×3=404.5026y
404.4708=404.5026y
y=404.4708/404.5026=>y=1 mol C10H18
nt=1+3=4 moli
%C10H8=1/4×100=25%