This equation contains four variables and if we know any three we can solve the equation to find the forth.
The units used for the equation are very important and we must be consinstent in their use. We will use SI units in this chapter. eg:
T =Temperature is in degrees Kelvin
P = Pressure is expressed in kilopascals (kPa)
V = Volume in litres
n = mole of the gas under investigation
R = 8.31JK^-1mole^-1