What is the density of chlorine gas at 1.21 atm and 34.9°C?

1 Answer
Dec 9, 2016

#rho=3.40*g*L^-1.#

Explanation:

We assume (reasonably) ideal gas behaviour.

And thus #PV=nRT#, else #n/V=P/(RT)#

#=# #(1.21*atm)/(0.0821*L*atm*K^-1*mol^-1xx307.9*K)#

#=# #0.0479*mol*L^-1#.

So, we have worked out a density in #mol*L^-1#, and we multiply this by the molecular mass in #g*mol^-1#.

And #70.9*g*mol^-1xx0.0479*mol*L^-1=3.40*g*L^-1.#

From where did I get the figure #70.9*g*mol^-1#?