[darknietzsche]

I am having trouble beginning a combustion analysis problem and am wondering if someone could steer me in the right direction.

A compound weighing 5.714mg produced 14.414 mg of CO₂ and 2.529 mg of water upon combustion. Find the weight percent of of C and H in the sample.

Here is what I know:

aX(unknown compound) bCO₂ + cH₂O where a,b, and c are coefficients to balance the equation

The above equation is something I assumed and not something given to me in the problem, if the equation is at fault please tell me.

moles of CO₂= 3.276E-4
moles of H₂O= 1.405E-4

All I want to know is maybe what i should look into doing next, if anyone could please help me it would be greatly appreciated!

[Borek]

What is a mass of carbon in produced CO₂? Does it differ from the mass of carbon in 5.714 mg of the substance?

[darknietzsche]

From that logic which does make sense...I get that there is 3.93mg of Carbon and .2809 mg of Hydrogen. Which these numbers work. Can you assume in this situation that the rest of the mass of the sample is some other element probably Oxygen?

[Borek]

Can you assume in this situation that the rest of the mass of the sample is some other element probably Oxygen?

That's a standard procedure, unless you know something more (like it is not oxygen, but nitrogen).

[darknietzsche]

Thank you very much. I am getting the hang of it.