(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Its the end of the year in my AP chemistry class and one section of our lab final includes finding the molar mass of an unknown gas. we are given a balloon filled with the gas and we must conduct any tests to figure the molar mass out

2. Relevant equations

pv=nrt

i believe the equation relating density and molecular weight is MW=drt/p

d=m/v

3. The attempt at a solution

heres what i've thought of

measure the weight of the filled balloon (our scales go up to 2 or 3 decimals)

fill a graduated cylinder with water, flip it upside down in a bucket of water and release the gas into the graduated cylinder to get the volume

then dry the balloon and get the weight again

use d=m/v to get the density and then use the above equation to calculate the MW

however i have some problems with this strategy

will the presence of gas effect the mass of the balloon (noting the sig figs of the scale)

what temperature do i use for mw=drt/p, the temp of the water or room temp?

if you have a diff strategy or any suggestions PLEASE let me know

thanks!

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# Homework Help: Lab Final - finding molar mass of an unknown gas

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