Question

O hidrocarbura A,cu masa molara =86g/mol,contine 83,72%C.
a)Sa se determine formula molara a hidrocarburii A .

Answer 1

Notam hidrocarbura CxHy
Deducem procentul de H; 100-83,72--> 16,28%H

Deducem nr moli C;83,72g/12g/mol=>6,98moliC
                nr.moli H:16,28g/1 g/mol==> 16,28moliH
iImpartind la cel mai mic, rezulta raportul molar:1 at C /2,33 at H

Formula bruta  (CH₂ ₃₃)n
Formula moleculara :  n(12+2,33)=86--->n=6---> C6 H14- HEXAN
CH3-CH2-CH2-CH2-CH2-CH3