Specific Latent Heat

• What happens to particles as a substance is heated?

  Particles gain energy in their kinetic energy store
• How does temperature relate to internal energy?

  Temperature measures average internal energy of particles
• What occurs during a change in state when heating a substance?

  Energy weakens or breaks forces between particles
• What happens to temperature during a state change?

  Temperature remains constant until state change completes
• What is the term for energy required to change state without temperature change?

  Latent heat
• What does specific latent heat (SLH) refer to?

  Energy to change 1 kg of substance's state without temperature change
• What are the two types of specific latent heat?

  Latent heat of vaporization and fusion
• What is the specific latent heat of vaporization?

  Energy change when a substance changes between liquid and gas
• What is the specific latent heat of fusion?

  Energy change when a substance changes between solid and liquid
• What happens to the temperature of ice at 0 degrees Celsius when it melts?

  Temperature remains constant during melting
• What is the specific latent heat of fusion for water?

  334,000 joules per kilo
• What is the specific latent heat of vaporization for water?

  2,260,000 joules per kilo
• What happens to the temperature of water at 100 degrees Celsius when it boils?

  Temperature remains constant during boiling
• What is the equation for specific latent heat?

  Energy = mass × specific latent heat
• How much energy is required to boil 2.5 kg of water at 100 degrees Celsius?

  5,650,000 joules
• What are the stages of heating 1 kg of water from -50°C to 150°C?

  1. Ice at -50°C: Temperature increases
  2. Melting at 0°C: Temperature constant, energy used for fusion
  3. Liquid water from 0°C to 100°C: Temperature increases
  4. Boiling at 100°C: Temperature constant, energy used for vaporization
  5. Water vapor at 150°C: Temperature increases
• How does cooling a substance differ from heating it during state changes?

  • Cooling involves bond formation
  • Energy is released during cooling
  • Temperature remains constant during state changes