Diffusion 🐋

• What is the main learning objective of section 5.1.6 on diffusion?

  To explain diffusion using the particle model
• What are the key components of diffusion as described in the study material?

  • Movement of particles in gases and liquids
  • Random direction changes due to collisions
  • Spread from high to low concentration
• What happens to bromine gas when the lid is removed from the gas jar?

  Bromine gas gradually fills the upper gas jar
• How do particles in gases and liquids behave according to the study material?

  They are constantly moving and colliding randomly
• What is the definition of diffusion?

  Diffusion is the movement of particles from a region of high concentration to a region of low concentration
• What factors affect the speed of diffusion?

  • Temperature
  • Particle size
  • State of the diffusing substances
• How does temperature affect the speed of diffusion?

  Higher temperatures increase the speed of diffusion
• What happens to diffusion speed in gases compared to liquids?

  Diffusion happens more quickly in gases than in liquids
• Why does diffusion not occur in solids?

  Particles in solids cannot move from place to place
• Who discovered evidence for the movement of particles in 1827?

  Robert Brown
• What is Brownian motion?

  Brownian motion is the random movement of particles caused by collisions with fast-moving particles
• What evidence do we have for the existence of particles?

  Diffusion in gases and liquids provides evidence for particles
• How do the sizes of hydrogen chloride and ammonia particles affect their diffusion rates?

  Hydrogen chloride particles diffuse more slowly because they are bigger and heavier than ammonia particles
• What is the relationship between particle size and diffusion speed?

  Big, heavy particles diffuse more slowly than small, light ones
• What are the observable effects of diffusion in the experiment with hydrogen chloride and ammonia?

  • Formation of a white solid ring
  • The solid is closer to the hydrogen chloride end
  • Indicates different diffusion rates of the two gases
• What is the significance of the random movement of specks of dust in the air?

  It demonstrates the collision of fast-moving air particles with dust particles
• What are the summary questions related to diffusion?

  1. Complete sentences about particle movement.
  2. Describe evidence for diffusion.
  3. Predict which particle diffuses fastest based on mass.
  4. Explain constant movement and collisions of particles.
• What is the role of temperature in diffusion speed?

  Temperature affects the speed of diffusion by increasing it at higher temperatures
• How does the arrangement of particles in gases differ from that in liquids?

  Particles in gases are far apart, while in liquids they are closer together
• What can be inferred about the movement of particles in a gas compared to a liquid?

  Particles in a gas travel longer distances before colliding with each other
• What is the definition of diffusion in terms of particle concentration?

  Diffusion is the movement from a region of high particle concentration to a region of low concentration