Question

Se ard 30 cm cubi hidrocarbura gazoasa cu 300 cm cubi oxigen luat in exces fata de hidrocarbura. Dupa condensarea apei, rezulta 210 cm cubi gaze de ardere, care dupa absorbie intr-o solutie de reduc la 60 cm cubi. Sa se determine formula moleculara a hidrocarburii,stiind ca volumele sunt masurate in c.n

Answer 1

30cmcub/ /22,4cmcub/mol=>1,34mmol  CxHy
300cmcub............................13,4mmol O2

CxHy prin ardere---> xCO2 + y/2 H2O+ O2 exces

volumul Co2= (210-60)cmcub= 150cmcub-->
 n= 150/22,4=7mmolCo2=7mmolC
1,34mmol hidrocarbura.......7mmolC
1 mmol-------------------------x=5-mmol---------------> C5Hy

V.apa= vinitial- v final=300+30-210=>120cmcub; n= 120/22,4=5,357mmol
n,apa= 5,357mmol--> n,H= 2x5,357=10,714mmolH
1,34mmolhidroc................10,714mmol
1mmol.................................y= 8mmol------------------------> C5H8