1.1 Energy change = mass x
specific heat capacity x
change in temperature
1.1.1 Specific Heat Capacity -
Energy needed to raise 1 kg
of a substance by 1K
1.2 Solids - Fixed positions, strong attraction between molecules
1.3 Liquid - constantly moving, attraction between molecules
1.4 Gas - constant random motion, no attraction
1.5 Specific Latent Heat of fusion of vaporisation is
the thermal energy required to change the state
of 1kg of a substance
1.5.1 Energy change = SLH x mass
2 Ideal Gasses
2.1 Boyle's Law: pV=constant
2.2 Charles' Law: V/T=constant
2.3 Pressure Law: p/T = constant
2.4 - Large number of molecules in rapid random motion - Collision between molecules are elastic -
Gravitational force is negligible - no intermolecular forces except during collisions - total volumes of
molecules is negligible compared to the volume of the container -
2.5 pV=nRT n-number of moles, R-molar gas constant
2.5.1 R = 8.31 J mol^-1 K^-1
2.6 pV=NkT N-number of molecules, k-Boltzmann's constant
2.6.1 k = R/Avagadro's constant = 1.38x10 JK^-1
2.6.1.1 Avagadro's constant = 6.02x10^23 mol^1
2.6.2 For one molecule of gas
3 Pressure of Ideal Gasses
3.1 Pressure is the combined force of all the molecules colliding with the
walls of the container at any given time
3.1.1 The force a particle exerts in proportion to it's change of
momentum (2 x mass x velocity) when it rebound of a wall
3.2 c bar squared is the square of the mean speed of a particle
3.3 Real gasses are closest to ideal gasses when the pressure is low but the temperature is high
4 Internal Energy andTemperature
4.1 Change of state is a change in Internal energy, but not temperature
because molecules gain potential energy, not kinetic
4.2 Thermal energy is always transferred from higher temperature regions to lower ones
4.3 The higher the temperature - both the average and maximum speeds increase, and the speed
distribution in the gas also increases
4.4 When particles collide, sometimes they can either gain or lose speed (and energy), this doesn't alter the
total energy in the system
4.5 Internal Energy is the sum of the kinetic and potential energy of particles in the system
4.6 E=(3/2)kT
4.6.1 Average kinetic energy is proportional to Boltzmann's constant x absolute temperature