Question

What is the atomic mass of a gas that has `rho=2.50*g*L^-1` at a pressure of `0.974*atm`, and a temperature of `371*K`?

Answer 1

Given `PV=nRT`..........`"molar mass"` `~=` `80*g*mol^-1`

Explanation:

`P/(RT)=n/V=("mass"/"molar mass")/V`

And thus `"molar mass"="mass of gas"/(PV)xxRT`

All I have done is manipulate the equation,

So `"molar mass"="mass"/(V)xx(RT)/P`

But `"mass"/V="density", rho`

Finally, `"molar mass"=rhoxx(RT)/P`

`(2.50*g*cancel(L^-1)xx0.0821*cancel(L)*cancel(atm)*cancel(K^-1)*mol^-1xx371*cancel(K))/(0.974*cancel(atm))`

`=??*g*mol^-1`