Chemistry Please HELP
posted by Saira .
A 1.082 g sample of a component of the light petroleum distillate called naptha is found to yield 3.317 g CO2 and 1.584 g H2O on complete combustion
This particular compound is also found to be an alkane with one methyl group attached to a longer carbon chain and to have a molecular formula twice its empirical formula
The compound also has the following properties:
melting point: -154 C
boiling point: 60.3 C
density: 0.6532 g/mL at 20.0 C
specific heat: 2.25 J
DeltaH f = -204.6 kJ/mol
Use the masses of CO2 and H2O to determine the empirical formula of the alkane component.
First i calculated the number of moles of Carbon and Hydrogen present in the unknown:
Molar mass = 43.99
CO2 mass - 3.317 g
Molar mass: 18.01
Mass of H20- 1.584 g
moles = 0.08795
Since there are 2 hydrogens in H2O
the moles are 0.01760.
And then i divide the moles by the lowest number:
Carbon: 0.0754/ 0.0754 = 1
Hydrogen: 0.0879/ 0.0754 = 1.16
I am not sure what to do next...
You're on the right track but you didn't start quite right. You haven't taken into account the mass of the sample. I would have determined the %C and %H, then converted those to mols and found the ratio from that.
i figured that the answer was C3H7
I found the mass percentage of C and H. Then I calculated the mass of C and H with the percentage.
Then I used the calculated masses to determine the number of moles of C and H. With that, I divided out the moles with the smallest number of moles. You should have gotten 1:2.33333333. In which you multiply by 3, to get the answer