# What law can be used to calculate the number of moles of a contained gas?

Apr 19, 2017

The Ideal Gas Law or Avagadro's Law

#### Explanation:

The Ideal Gas Law (PV = nRT) can be used if you have pressure, volume, and temperature. Where...
...P = Pressure in kPa
...V = Volume in ${\mathrm{dm}}^{3}$
...n = The number of moles of gas present
...R = Universal Gas Constant ( $8.314$ )
...T = The temperature in Kelvin

If you don't have those pieces of information, perhaps Avagadro's Law will take care of you. It says that 1 mole of any gas at standard temperature and pressure will occupy $22.4 {\mathrm{dm}}^{3}$. The only limitation of this is, that you have to deal with the gas at STP (standard temperature and pressure); i.e. 298K and 100kPa