Temperature Changes

• What is specific heat capacity?

  The amount of energy required to raise the temperature of 1kg of a substance by 1 degrees
• What is the equation for change in thermal energy (specific heat capacity)?

  Change in thermal energy = mass x specific heat capacity x temperature change
• What is specific latent heat?

  The amount of energy needed to change the state of 1kg of a substance without a change in temperature
• Specific latent heat of fusion is energy to melt/freeze
• Specific latent heat of vaporisation is energy to boil/condense
• What is the equation of specific latent heat?

  energy for a change in state = mass x specific latent heat

  E = mL
• When is energy absorbed?

  When melting and evaporating
• When is energy released?

  When freezing and condensing
• What is sublimation?


  When solid goes straight to gas 'dry ice' (solid CO2 does this)
• How ice changes with temperature:

  A: it is solid. B: reaches 0 degrees. B to C: No temp change because the energy is used through melting. C to D: it is in liquid state. D to E: the water is boiling, takes longer because evaporation takes more energy. E to F: the gas is heating.

  
• The specific heat capacity of ice is less than the specific heat capacity of water. Explain why.

  • gradient for ice in graph is steeper than water
  • which means less energy is needed to change the state from solid to liquid
• The specific latent heat of fusion of ice is less than the specific latent heat of vaporisation of water. Explain why.

  • water took more time to vaporise than the ice took to mely
  • which means that less energy is needed to change the state from solid to liquid