Specific latent heat

• Melting and boiling = increases amount of internal energy

  -energy is used to break bonds

  -so temp dosent increase

  -on graph , this is shown as a straight line
• Melting and boiling graph

  straight lines = latent heat of fusion

  
• Condensing and freezing - energy put in is used to form bonds

  -releases energy

  -internal energy decreases

  -temperature doesnt go down
• Condensing and freezing

  
• Latent heat - energy needed to change states of substances
• has the amount of energy needed to change 1kg of a substance from one state to another without changing the temp
• Different for different material

  solid —> liquid - specific latent heat of fusion

  liquid —> gas - specific latent heat of vaporisation
• Equation : energy ( E ) = mass ( m ) x specific latent heat ( L )

  E = mL