08206cal/mol K1.987J/mol K8.314m3 Pa/mol K8.314L torr/mol K62.36Example:
If we had 1.0 mol of gas at 1.0 atm of pressure at 0°C (273.15 K), what would be the volume?
PV = nRT
V = nRT/P
V = (1.0 mol)(0.0821 L atm/mol K)(273 K)/(1.0 atm)
V = 22.41 L
0 °C and 1 atm pressure are referred to as the standard temperature and pressure (STP)
The molar volume of an ideal gas (any ideal gas) is 22.4 liters at STP
Example: Nitrate salts (NO3-) when heated can produce nitrites (NO2-) plus oxygen (O2). A sample of potassium nitrate is heated and the O2 gas produced is collected in a 750 ml flask. The pressure of the gas in the flask is 2.8 atmospheres and the temperature is recorded to be 53.6 °C.
How many moles of O2 gas were produced?
PV = nRT
n = PV/RT
n = (2.
