1 / 36

Phases of Matter

Phases of Matter. Solids. Particles are tightly packed in an orderly pattern . Can’t move about. Can only shake or vibrate. Memory Jogger. Gases. Particles are far apart and can move rapidly from place to place.

mthorne
Télécharger la présentation

Phases of Matter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Phases of Matter

  2. Solids • Particles are tightly packed in an orderly pattern. Can’t move about. Can only shake or vibrate. Memory Jogger

  3. Gases • Particles are far apart and can move rapidly from place to place. • Gases can move from place to place (translation), they can tumble (rotation), & they can shake (vibration). Memory Jogger

  4. Liquids • There is a little space between particles & they can slide past each other. Little or no order. • Liquids can vibrate & have very hindered translation and rotation – the particles can move a little bit but then they bump into a neighbor.

  5. Liquids Condensed phases = liquid & solid phases. Particles are close together.

  6. Kinetic Energy • Atoms & molecules are in constant motion. • Temperature is an assessment of the average K.E. of the particles in a sample of matter. • If the temperature , the avg. K.E. • If temperature , then avg. K.E. Memory Jogger  

  7. Temperature vs. Motion • A gas & a solid at the same temp have the same avg. K.E., but the particles in the 2 phases move very differently.

  8. Why do liquids & solids exist? What holds them together?

  9. Intermolecular Forces • There are attractive forces between all particles of matter called intermolecular forces. • Intermolecular forces arise because atoms contain charged particles – protons & electrons. • Not as strong as bonding within a molecule, but intermolecular forces are responsible for solids & liquids.

  10. Intermolecular Forces • All molecules are attracted to each other. • Some molecules are strongly attracted & some are only weakly attracted. • If it wasn’t for intermolecular forces,everything would be a gas!!!

  11. What is a phase change? • A transition between phases. There are 6. What are they?

  12. Boiling or Vaporization source H2O(l)  H2O(g)

  13. H2O(s)  H2O(l) source source Melting or Fusion

  14. I2(g)  I2(s) Deposition I2(s)  I2(g) Sublimation source

  15. H2O(g)  H2O(l) Condensation source

  16. H2O(l)  H2O(s) Freezing source

  17. Chunk of dry ice in water. source

  18. Phase Changes • When a substance goes from the gas to a condensed phase, what happens? • The particles get closer together and their translational motion (movement from point A to point B) slows down. • We cool it and/or compress it.

  19. Gas to Liquid

  20. Phase Changes • When a substance goes from a solid to a liquid or a gas, what happens? • The particles move far apart and their translational motion increases. • We heat them up and/or reduce the pressure.

  21. Phase is determined by the competition between kinetic energy & intermolecular forces

  22. Kinetic Energy vs.Intermolecular Forces

  23. Kinetic Energy  Intermolecular Forces • Weak intermolecular forces: even with low K.E. the particles can “escape” from one another & move far apart. • Move the magnets past each other quickly. Can the magnet in your right hand feel the magnet in your left hand? • What phase has weak intermolecular forces? Gas phase

  24. Intermolecular Forces  Kinetic Energy • Strong intermolecular forces: the particles may be trapped next to each other unless they are moving fast. • Move the magnets past each other slowly. What happens? • What phase has strong intermolecular forces? Solid phase

  25. Solid Phase – strong intermolecular forces • The stronger the intermolecular forces, the higher the melting point & boiling point. • Gas Phase – weak intermolecular forces • The weaker the intermolecular forces, the lower the melting point & boiling point.

  26. Sublimation • What can you say about the intermolecular forces in I2? (I2 sublimates.) • They are pretty weak!

  27. Particle Diagram of I2 White lines represent forces of attraction between I2 molecules.

  28. Potential Energy of a Pure Substance • Equal quantities of ice & water at 0C have the same kinetic energy, although the molecules move differently in the 2 phases. • They have different potential energy. • The farther apart the particles, the greater the potential energy. • For potential energy, gases  liquids  solids.

  29. Potential vs. Kinetic Energy of H2O • How can I start with H2O at 0C and raise the temperature to 50C? • I have to add energy to the system and it increases the kinetic energy of the water molecules. They move faster.

  30. Potential vs. Kinetic Energy of H2O • How can I start with ice at 0C and convert it to water at 0C? • I have to add energy to the system and it increases the potential energy of the particles. They move father apart from one another.

  31. Gas Going Up the ladder = Endothermic Process Net gain in energy. Potential Energy of System Liquid Going Down the ladder = Exothermic Process Net loss in energy. Solid

  32. Gas Going Up the ladder… Endothermic Process (Net gain in energy ) Potential Energy of System Liquid Going Down the ladder… Exothermic Process (Net loss in energy ) Solid

  33. source

  34. source

  35. Q = mCgT Q = mClT Q = mHv Q = mCsT Q = mHf Temperature Time

More Related