What is the volume of #2# #mol# of oxygen, #O_2#, at STP?
You need to specify (i) a pressure, and (ii) a temperature, before the molar quantity can be calculated.
If we assume standard laboratory conditions,
Assuming that the gas is at standard temperature and pressure (STP), one mole of any gas occupies
The Ideal Gas Law makes certain assumptions about the gases: that the particles are very tiny and featureless and that there is no force acting between them. If these assumptions are correct, then one mole of any gas will occupy
The assumptions are not quite the case for