Ideal+gas+equation

=__An ideal gas__=

By Louisa Hitchen ( she smells)
For a few gases, you can liquefy by just raising the pressure, but for a lot of gases, you have to lower the temperature as well

Each gas has a CRITICAL TEMPERATURE, so below this temperature the gas can be liquefied by applying the necessary pressure, but above the critical temperature, the gas cannot be liquefied whatsoever.

The pressure law states that for a fixed mass of gas at constant volume, the pressure is directly proportional to the Kelvin Tempearture. From this we can work out that the pressure divided by the temperature produces a constant
 * p/t = constant.**

We also know from Boyle's Law that for a fixed mass of gas at a constant temperature, the product of the pressure and volume is constant
 * pressure * volume = constant**

or **pV = constant**
so, if pV = constant, and p/t constant, then the 2 equations combined are:
 * pV/t = constant**

The value of the constant depends on how much gas is present, so for 1 mole of gas, (containing 6.023 * 10^23molecules), this constant is **R, the molar gas constant pV/t = R for 1 mole of gas**

__Example:__ The volume of 1 mole of gas at atmospheric pressure (101400Nm^ -2) and a temperature of 273K is 0.0224m^3. From this you can calculate R: =101400 * 0.224/273 = 8.3 NmK ^ -1 = 8.3 JK ^ -1
 * R =** **pV/t**

A mass m of gas contains m/M moles where M is the molar mass (the mass of one mole). So for a mass m:

pV/t = (m/M)R
or

pV = (m/M)Rt

 * This equation is known as the ideal gas equation**