View Full Version : Chemistry Problem

05-12-2008, 09:38 PM
Ok, so i have this lab on the molar mass of butane, except im totally having a brain fart, and cant remember how to do it, like i have the PV=nRT, but once i have the number from there im stuck, any ideas?

05-12-2008, 11:36 PM
Oooh this is right up my ally. I just finished college Chemistry.


n = moles

Molar Mass = Mass of gas/N

I'm fairly certain, anyway.

If you could give me the exact problem I'm pretty sure I could do it. My best unit in Chem was the gas laws.

Is this by chance Webassign?

05-13-2008, 03:43 AM
CH3CH2CH2CH3 is butane, I forget if that helps, it's been 3 years since I took chemistry. I was under the impression that you could find the atomic mass of each atom in the substance, add them up then multiply it by Avogadro's number, 6.02214×10^23, which is how many molecules per mol there are. I'm nearly certain now that's wrong or inaccurate to anything aside from 20* Celsius at 1atm pressure because you'll have to account for the mass gain due to excess energy.

I found this while googling: http://www.chem.uiuc.edu/chem103/molar_mass/introduction.htm