The General Gas Equation Combined Gas Law P1V1 n1T1 = P2V2 n2T2

Ideal Gas Equation

Combining the Gas Laws: The Ideal Gas Equation is derived using the Ideal Gas Constant P Boyle’s law V  1/P Charles’s law V  T Avogadro’s law V  n nT Any gas whose behavior conforms to the ideal gas equation is called an ideal or perfect gas. R is the gas constant. Substitute and calculate. V = R P PV = nRT

The Gas Constant PV = nRT PV R = nT = 0.08206 L atm/mol K = 1.207 L psi / mol K = 8.314 Pa m3 / mol K = 8.314 J/mol K = 62.36 L Torr/ mol K

The General Gas Equation P1V1 n1T1 = P2V2 n2T2 R =

Example A 5.0 L cylinder contains oxygen gas at 20.0°C and 735 mm Hg. How many grams of oxygen are in the cylinder? Catalog Variables P = 735 mmHg V = 5.0 L n = # moles O2 R = 0.08206 L atm / mol K T = 20 °C

Example P = 735 mmHg 1 atm = 0.967 atm 760 mmHg Convert Units V = 5.0 L n = # moles O2 R = 0.08206 L atm / mol K T = 20 °C + 273 = 293 K 0.201 mol O2 32.0 g O2 = 6.43 g O2 1 mol O2 Solve Equation = 0.201 mol O2

Molar Mass Determination and n = m MM PV = nRT PV = m MM RT m RT m RT MM = MM = PV PV P MM dRT d = MM = RT P