You have a 1 L container of a gas at 20°C and 1 atm. Without opening the container, how could you tell whether the gas is chlorine or fluorine?
The ideal gas equation is
Asuming the mass of the container is negligible,
Determine the mass of the container plus gas.
This assumes that you know the mass of the container.
We can use the Ideal Gas Law to calculate the mass of the gas.
#color(blue)(bar(ul(|color(white)(a/a)pV = nRT = m/MRTcolor(white)(a/a)|)))" "#
#m = (pVM)/(RT)#
If the gas is chlorine,
If the gas is fluorine,
Thus, if the mass of container plus gas is 2.9 g more than the mass of the empty container, the gas is chlorine.
If the mass difference is only 1.6 g, the gas is fluorine.