Question

In conditii normale 1 dm³ dintr-o hidrocarbura gazoasa cantareste 2,5 g.In urma arderii a 0,2 moli de aceeasi hidrocarbura se degaja 35,2 g CO₂. Determina formula moleculara a hidrocarburii si scrie o formula de structura, stiind ca ea contine o legatura π.

Answer 1

m/M=V/Vm => M=m*Vm/V=2,5*22,4/1=56g/mol

44g CO2..................12g C
35,2g CO2...............x=9,6g C

n=m/M=9,6/12=0,8 moli C

0,2 moli CxHy.................0,8 moli C
1 mol..............................x=4 atomi C

Fiind o hidrocarbura nesaturata ar putea fi o alchena => CnH2n

Formula moleculara ar fi -> C4H8 -> butena

CH2=CH-CH2-CH3