Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: jennielynn_1980 on September 23, 2011, 04:44:29 PM
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Hi everyone. I have figured out most of this question but the last part is really getting me. I haven't been in a chemistry class for awhile so I am a little rusty. If someone could tell me what direction to think in that would be great :)
A sample of 2.14 g of a gaseous organofluorine compound occupies a volume of 2.00 L at 25.5 C and 30.2 kPa. What is the molar mass of this compound and what is it's formula?
So using PV=nRT
n= (0.298atm)(2.00L)/(0.08205 L atm K-1 mol-1)(298.65 K)
= 0.0243 mol
Then using M=m/n
M = 2.14g/0.0243 mol
= 87.9 g/mol
So I determined the molar mass but now how do I get the formula?
Thanks :)
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The only possible approach is by trial and error. Start with simple compounds (like CH3F) and see if they fit the molar mass.
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Thank you Borek. I was trying to figure out how to do a percentage my mass setup but I wasn't getting far.