# Question #2f5b5

Oct 21, 2014

Use the fact that a mole of any gas occupies a volume of 24L at room temperature and pressure.

Here is an example: "What is the volume occupied by 2.2g of $C {O}_{2}$ at room temperature and pressure ? "

The ${M}_{r}$ of $C {O}_{2}$ is 12 + (2 x 16) = 44

so 44g occupies 24L
so 1g occupies 24/44 = 0.5 L
So 2.2g occupies 0.5 x 2.2 = 1.1L

If we are not under standard conditions you may to use The Ideal Gas Equation:

$P V = n R T$

Where P = pressure
V = volume
T = the absolute temperature
n = the no. of moles
R = the gas constant = 8.31J/K/mol