AS Chemistry Mole Question

Hi y'all.
I've been doing chem calculations for the last hour and i've tried this one but i cant seem to tackle it so any help would be appreciated!

A gas has a density of 1.655g dm^(-3) at 323K and 1.01 x 10^5 Pa. Calculate the Mr of the gas.

Thanks to anyone who can help!! :biggrin:

Reply 1

papz_007

try using pv=nrt to find ammount of moles, when use n=m/M

rearrange the eqauation

let me no if that helps

Reply 2

papz_007

sorry ...shud of said not sure about this im sure some1 will correct me if im wrong

Reply 3

Aired

Well one mole of a gas occupies 24dm^3 at room temperature (Is that 323k? I'm not sure...)

That means that 1/24 moles of the substance weighs 1.655g

So if you multiply this weight by 24, you will get the mass of one mole of the substance (the Mr) , which turns out to be 39.72.