Ideal Gas Equation

• The volume of a gas at temperatures and pressures other than RTP can be calculated using the ideal gas equation.
• The assumptions are:

  -Gases are made up of molecules which are in constant random motion in straight lines.

  -The molecules behave as rigid spheres.

  -Pressure is due to collisions between the molecules and the walls of the container.

  -All collisions, both between the molecules themselves, and between the molecules and the walls of the container, are perfectly elastic.

  -The temperature of the gas is proportional to the average kinetic energy of the molecules.
• The 2 key assumptions:

  -There are no IMFs between the gas molecules.

  -The volume occupied by the molecules themselves is entirely negligible relative to the volume of the container.
• The ideal gas equation is pV=nRT where p is the pressure, V is volume, n is the number of moles, R is the universal gas constant, and T is the absolute temperature
• What does p represent in pV=nRT?

  Pressure.
• What does V represent in pV-nRT?

  Volume.
• What does n represent in pV-nRT?

  Amount of gas in mol.
• What does R represent in pV-nRT?

  The ideal gas constant --> 8.314.
• What does T represent in pV-nRT?

  Temperature.
• What are the units of pressure in pV=nRT?

  Pa.
• What are the units of volume in pV=nRT?

  $m^3$
• What are the units of n in pV=nRT?

  mol
• What are the units of R in pV=nRT?

  $J mol^-1 K^-1$
• What are the units of T in pV=nRT?

  Kelvin
• What is the ideal gas constant?

  8.314 $J K^-1 mol^-1$
• Pascals is the same as N/m^2 or N/m^3
• $1m^3 =$$1000dm^3 =$$1,000,000cm^3$
• $0^OC =$$273K$
• If given temperature in Celsius, add 273 to convert to Kelvin.
• $p =$$nRT/V$
• $V =$$nRT/p$
• $n =$$pV/RT$
• $T =$$pV/nR$
• Calculate the pressure, in kPa, that a 2.05 mol sample of oxygen would exert if in a 52.3cm3 container at 1255K.

  = 4.09 x 10^5 kPa