[hwgw]

I am given:

m=0.2408 ± 7*10^-4 g
T = 20.50 ± .10 degrees C
P = 752.67 ± 0.1 mm of Hg
V = 143.584 ± 0.20 mL

I was told to find the molar mass and its uncertainty. I was able to find the molar mass through

PV=nRT
PV=mRT/M
M=mRT/PV where R=0.08206

But how can i find the uncertainty of the molar mass? I tried converting the uncertainties to their correct units corresponding the equation PV=mRT/M, but that was wrong.

Thanks

[Borek]

No idea how you were told to do such things - and there are methods for error propagation calculations, that should be shown to you before asking the question. If they were not, and you are just tested to see if you know how to use your own brain to solve new problems, you may try "crank three times" method:

http://www.av8n.com/physics/uncertainty.htm#htoc11