hey guys me and my roomie need help with a chemistry question, so if anyone knows how to do this PLEASE explain it to us!

OK..What is the empirical formula of a hydrocarbon if complete combustion or 1.100 mg of the hydrocarbon produced 3.625 mg of CO2 and 0.989 mg of H2O?

8/28/2008 9:43:12 PM

you know the amounts of carbon and hydrogen, and their proportion...

8/28/2008 9:48:54 PM

yea but uhm...we dont know what to do with the information we have...or we would have done it..

8/28/2008 9:50:48 PM

the proportion will be the same in the reactants and the products

[Edited on August 28, 2008 at 9:57 PM. Reason : it's prolly propane]

8/28/2008 9:54:41 PM

not propane

8/28/2008 10:20:35 PM

haha, just a guess--seems like back in the day the answer was always propane

8/28/2008 10:29:02 PM

jesus christ

8/28/2008 10:47:40 PM

And so it begins ...

Formulas involve mol ratios; for a hydrocarbon, mol ratios of C & H.
Given mass info for CO2 and H2O;
Convert to mol info for same;
Convert to mol info for C & H;

... and so it is done.

8/28/2008 11:02:29 PM

im guessing this was for 201 and if you bought the textbook theres a question exactly like that on page 8/9

8/28/2008 11:34:28 PM

Quote :

"yea but uhm...we dont know what to do with the information we have...or we would have done it.."

you do have a book, right?

[Edited on August 28, 2008 at 11:52 PM. Reason : most any intro chem book should mention combustion]

8/28/2008 11:52:21 PM