The ideal gas equation

• what does the kinetic theory of gases state ?

  that molecules in gases are constantly moving
• what assumptions does the the kinetic theory of gases make ? state 3

  • That gas molecules are moving very fast and randomly
  • That molecules hardly have any volume
  • That gas molecules do not attract or repel each other (no intermolecular forces)
  • No kinetic energy is lost when the gas molecules collide with each other (elastic collisions)
  • The temperature of the gas is related to the average kinetic energy of the molecules
• what are the gases that fit the kinetic theory called ?

  ideal gases
• what does the volume that an ideal gas occupy depend on ?

  • pressure
  • temperature
• describe how temperature affect the volume that gas occupies ?

  • hen a gas is heated (at constant pressure) the particles gain more kinetic energy and undergo more frequent collisions with the container wall
  • To keep the pressure constant, the molecules must get further apart and therefore the volume increases
  • The volume is therefore directly proportional to the temperature (at constant pressure)
• what are some limitations of the ideal gas law ?

  Real gases deviate from ideal behavior at high pressures and low temperatures
• why do real gases deviate from ideal behavior at high pressures and low temperatures ?

  under these conditions:

  • Molecules are close to each other
  • There are instantaneous dipole- induced dipole or permanent dipole- permanent dipole forces between the molecules
  • These attractive forces pull the molecules away from the container wall
  • The volume of the molecules is not negligible
• what is the ideal gas equation and units for each ?

  PV = nRT

  P = pressure (pascals, Pa)

  V = volume (m3)

  n = number of moles of gas (mol)

  R = gas constant (8.314 J mol-1 K-1)

  T = temperature (kelvin, K)
• why may , in a lot of reactions, not all reactants react to form products ?

  • Other reactions take place simultaneously
  • The reaction does not go to completion
  • Products are lost during separation and purification
• what does the percentage yield show ?

  The percentage yield shows how much of a particular product you get from the reactants compared to the maximum theoretical amount that you can get
• What's the percentage yield equation ?

  percentage yield = actual yield / theoretical yield x 100
• what does the atom economy show ?

  The atom economy of a reaction shows how many of the atoms used in the reaction become the desired product
• what is the equation for atom economy ?

  atom economy = molecular mass of desired products /sum of molecular masses of all reactants x 100
• in addition reactions the atom economy will always be .....

  100%
• How can atom economy also be calculated by using mass instead of Mr ?

  • In this case, you would divide the mass of the desired product formed by the total mass of all reactants, and then multiply by 100
• what does a high percentage yield suggest ?

  that a process is effective at converting reactants into products
• what is the estimated percentage yield for a single run of the harber process and why is there a compromise ?

  The estimated percentage yield for a single run of the Haber Process is around 15%

  • This is a compromise due to the cost and safety of the required conditions against the overall rate of ammonia production
• How can Green Chemistry help reduce waste and costs in chemical reactions?

  By choosing reaction pathways with fewer steps, higher atom economy, and high percentage yield, reducing waste, energy demands, and production costs