CHEMISTRY chapter 2 : Kinetic particle theory

• What is diffusion?

  Movement of particles from high to low concentration
• In which state of matter is the rate of diffusion fastest?

  In the gaseous state
• Why is the rate of diffusion fastest in gases?

  Particles are moving in all directions
• How does temperature affect the rate of diffusion?

  Higher temperature increases the rate of diffusion
• What happens to particle movement at higher temperatures?

  Particles have more kinetic energy and move faster
• What is the relationship between relative molecular mass and the rate of diffusion?

  Slower the mass, faster the rate of diffusion
• Calculate the relative molecular mass of O₂.

  $32$
• Calculate the relative molecular mass of N₂.

  $28$
• Calculate the relative molecular mass of H₂.

  $2$
• Calculate the relative molecular mass of CO₂.

  $44$
• What happens to the water level when CO₂ particles diffuse into a beaker?

  Water level decreases as gas molecules increase
• What are the key features of heating curves?

  • Temperature increases over time
  • Changes in state occur at specific points
  • Melting point: 0°C
  • Boiling point: 100°C
• Why does temperature remain constant during melting or boiling?

  Heat energy converts to kinetic energy
• What happens to particles during melting?

  Particles gain energy to overcome attractive forces
• What are the boiling and melting points of pure and impure H₂O?

  • Pure H₂O:
  • Boiling point: 100°C
  • Melting point: 0°C
  • Impure H₂O:
  • Boiling point: 105-110°C
  • Melting point: -5 to -10°C
• What is the boiling point range of impure H₂O?

  105-110°C
• What is the melting point range of impure H₂O?

  -5 to -10°C
• How do particles in a solid behave?

  They vibrate in fixed positions
• How do particles in a liquid behave?

  They slide over one another
• How are particles arranged in a gas?

  They are far apart and move freely
• What is the arrangement of particles in a solid?

  Very closely packed in a fixed arrangement
• What is the arrangement of particles in a liquid?

  Closely packed in an irregular arrangement
• What is the effect of temperature on particle movement in solids?

  Particles vibrate faster at higher temperatures
• What is the effect of temperature on particle movement in liquids?

  Particles move faster at higher temperatures