Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: What is the empirical formula of the compound?

  1. Jan 28, 2007 #1
    A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.8635 g of CO2 and 0.1767 g of H2O. What is the empirical formula of the compound? I don't know how to figure this out without percentages of each element.
  2. jcsd
  3. Jan 28, 2007 #2
    i can help you! i can help you!

    yeah..this is one of those hard stochiometry problems. but nofear; my teacher told us how to do these a month ago, so i can help you :)

    kk..you have to think of it like this:
    CxHyOz ---> CO2 + H2O

    so for CO2, you find the grams of carbon by...
    (12.01 g C) / (44.01 g CO2) = 0.27 g (0.8635) = 0.233 g C in CO2
    and for H2O, you do the same thing...
    (2.02 g H) / (18.02 g H2O) = 0.11 g (.1767) = 0.0194 g H in H2O
    and for O, you do...
    (0.4647) - (0.233+0.0194) = and get grams of O
    and then you can do the rest...i'm getting tiredd lol.

    hope that helped! :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook