What is the volume of 22 molmol of oxygen, O_2O2, at STP?

2 Answers
Feb 29, 2016

You need to specify (i) a pressure, and (ii) a temperature, before the molar quantity can be calculated.

Explanation:

If we assume standard laboratory conditions, 2525 ""^@CC and 11 atmatm (or thereabouts; the standard is slightly different now!), 2L2L dioxygen gas represents, (2L)/(25.4*L*mol^-1)2L25.4Lmol1 ""approx 1/12*mol 112mol.

Feb 29, 2016

Assuming that the gas is at standard temperature and pressure (STP), one mole of any gas occupies 22.422.4 LL. This means the number of moles of O_2O2 is 2/22.4=0.089222.4=0.089 molmol.

Explanation:

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 22.422.4 LL at STP.

The assumptions are not quite the case for O_2O2, but the deviations from it are small enough that we can still use this approach and receive an accurate answer.