1、理想气体状态方程(ideal gas，equation of state of)，也称理想气体定律或克拉佩龙方程，描述理想气体状态变化规律的方程。

2、质量为m，摩尔质量为M的理想气体，其状态参量压强p、体积V和绝对温度T之间的函数关系为pV=mRT/M=nRT 式中M和n分别是理想气体的摩尔质量和物质的量;R是气体常量。

3、对于混合理想气体，其压强p是各组成部分的分压强p p2、……之和，故 pV=( p1+ p2+……)V=(n1+n2+……)RT，式中nn2、……是各组成部分的摩尔数。

4、 以上两式是理想气体和混合理想气体的状态方程，可由理想气体严格遵循的气体实验定律得出，也可根据理想气体的微观模型，由气体动理论导出。

5、在压强为几个大气压以下时，各种实际气体近似遵循理想气体状态方程，压强越低，符合越好，在压强趋于零的极限下，严格遵循。

6、The Ideal Gas Law ( PV = nRT ) is unlike the other gas laws in that it does not require an initial and a final state, that is it does not require the situation to CHANGE in order to determine a value for Pressure, Volume, amount of gas or Temperature.PV = nRTWhere R = 0.082 atm*L/mole*KWe can determine the Pressure, Volume, Temperature or amount of a gas (n) when the others are known. For this we must use Pressure in atmospheres, Volume in Liters, amount of gas in moles and Temperature in Kelvin.If you know the pressure, temperature and volume of a gas you can determine the number of moles.Pressure = 1.4 atmVolume = 500ml ->convert to Liters ->0.5 LTemperature = 20 degrees Celsius ->convert to Kelvin ->293KWhich gives us:PV = nRT (1.4 atm)(0.5 L) = (n)(0.082 atm*L/mole*K)(293K) n = 0.029 moles --------------------------------------------------------------------------------At S.T.P.In order to standardize research and results scientists use a Standard Temperature and PressureThe Temperature and Pressure are 273K and 1 Atm.If we plug those number in the equation with a quantity of 1 mole we get the volume of a mole of ANY GAS:PV = nRT (1 atm)( V ) = (1 mole)(0.082 atm*L/mole*K)(273K) V = 22.4 L The volume of ANY GAS at S.T.P. is 22.4 Liters.