Kinetic Particle Theorey | Chemistry




  1.  Kinetic Particle Theory
  2.  What is Kinetic Particle Theory The kinetic particle theory states that all matter is made up of tiny particles and that these particles are in constant, random motion.
  3.  Uses of the Kinetic Particle Theory • Describes the states of matter • Explains the differences in the properties of solids, liquids and gases • Explains the changes of states
  4.  Three States of Matter ICE WATER STEAM Solid Liquid Gas
  5.  Particles and properties
  6.  Properties of Solid, Liquid & Gas Properties Solid Liquid Gas Sample picture of how the particles are arranged Shape Volume Compressibility Fixed Fixed Fixed Not fixed Not fixed Not fixed Cannot be compressed Cannot be compressed Can be compressed
  7.  How do particles move?
  8.  Properties Solid Liquid Gas Motion of molecules Arrangement of molecules Intermolecular forces Distance between molecules Energy of the particles Vibrations about fixed position only Arranged in fixed and orderly arrangement Slide past & movement through liquid No fixed arrangement Vibrations and movement anywhere No fixed arrangement Very strong Weak Negligible Packed very close together Not so closely packed Very far apart According to Kinetic Particle Theory Less energy than liquids or gases More energy than solids but less than gases More energy than solids or liquids
  9.  Properties Solid Liquid Gas Shape Reason: Reason: Reason: Volume Reason: Reason: Reason: Compressibility Reason: Reason: Reason: Fixed Fixed Fixed Not fixed Not fixed Not fixed Cannot be compressed Cannot be compressed Can be compressed • Particles are held together by strong forces of attraction. • Vibrate about fixed positions & cannot move about freely. • Particles are held together by weaker attractive forces • Not held in fixed positions • Move freely by sliding over one another • Forces of attraction between particles are very weak • Not held in fixed positions • Move rapidly in any direction • Particles are packed very close to one another • Particles are packed very close to one another • Almost no empty spaces between particles • Particles are further away from one another • Particles are still packed quite closely together • Particles are further away from one another • Particles are still packed quite closely together • Large space between particles • Can be forced to move closer together • Large space between particles • Can be forced to move closer together Relating Properties of Solid, Liquid & Gas to the Kinetic Particle Theory
  10. Cornflour paste: solid or liquid?
  11. Multiple-choice quiz
  12. . Changes of State Is it reversible?
  13.  SOLID LIQUID GAS 1. M ELTING Changes of State
  14.   Melting What happens to the particles of a solid that is heated until it melts? As heat energy is supplied to the solid and converted into kinetic energy, the particles vibrate faster about their fixed positions. When the vibrations of the particles overcome the attractive forces between them, they begin to break away from their fixed positions. The particles slide over one another and the substance is now a liquid. Heat energy
  15. Heating Curve (Melting) Temperature/o C Time/min A à B: Solid heats up. The temperature of the solid increases until it reaches point B, its melting point. At point B, the solid begins to melt. B à C: Solid melts. A mixture of solid and liquid exists here. During the melting process, the temperature of the substance remains constant even though heating continues. All the heat energy taken in by the particles is used to overcome the forces of attraction between particles. C à D: Liquid heats up. At point C, all the solid has melted and the temperature of the liquid rises as heating continues.
  16. SOLID LIQUID GAS 2. FREEZING 1. Melting Changes of State
  17. . Freezing Energy is given out by the particles of the liquid. They lose kinetic energy and begin to move more slowly. When the temperature is low enough, the particles do not have enough energy to move freely. Some particles start to settle into fixed positions. Finally, all the particles settle into fixed positions. Particles can only vibrate about their fixed positions. The substance is now a solid. What happens to the particles of a liquid that is cooled until it freezes?
  18. Cooling Curve (Freezing) Temperature/o C Time/min P – Q: Liquid cools. The temperature of the liquid drops until it reaches point Q, the freezing point of naphthalene. At point Q, the liquid starts to freeze. Q – R: liquid freezes. A mixture of liquid and solid exists here. During the freezing process, the temperature of the substance remains constant even though cooling continues. R – S: solid cools. At point R, the substance has solidified. The temperature of the solid continues to drop as it is cooled.
  19.  SOLID LIQUID GAS 3. Evaporation / Boiling 2. Freezing 1. Melting Changes of State
  20.   Boiling As the liquid is heated, the particles gain kinetic energy and start to move faster. Eventually, the particles have enough energy to overcome the attractive forces holding them together. They spread far apart and move rapidly in all directions. The substance is now a gas.
  21. Heating Curve (Boiling) Temperature/o C Time/min When a liquid is heated, its temperature increases till its boiling point is reached. Here, it boils and changes into a vapour. Temperature remains constant till all the liquid has boiled off. Heat energy taken in is used to overcome forces of attraction between the particles of the liquid and to make the particles move further apart. X Y The temperature remains constant till all the liquid has boiled off Z
  22. SOLID LIQUID GAS 3. Evaporation / Boiling 2. Freezing 1. Melting Changes of State
  23.  Evaporation Evaporation occurs because some particles have enough energy (more kinetic energy) to escape as a gas from the surface of the liquid. Volatile liquids are liquids that evaporate quickly at room temperature. E.g. Petrol and perfumes.
  24. Differences between Evaporation & Boiling Evaporation Boiling • Occurs at temperatures below boiling point • Occurs only at the surface of the liquid • Occurs slowly • Occurs only at boiling point • Occurs throughout the liquid • Occurs rapidly
  25. SOLID LIQUID GAS 4. Condensation 3. Evaporation / Boiling 2. Freezing 1. Melting 4. Sublimation Changes of State
  26.  Condensation • Condensation occurs when a gas is cooled sufficiently to change into a liquid.
  27. Eventually, the movement of the particles becomes slow enough for the gas to change into a liquid / move closer to slide past one another. Heat energy is given out, and the gas particles lose energy and move more slowly as the temperature drops. 4. Condensation
  28. SOLID LIQUID GAS 4. Condensation 3. Evaporation / Boiling 2. Freezing 1. Melting 4. Sublimation 5. Condensation Changes of State
  29.  Sublimation Dry ice sublimes • Sublimation involves changing solids directly into a gas without going through the liquid state. • Examples of substances undergoing sublimation: 1. Dry ice (Solid carbon dioxide) 2. Solid Iodine 3. Ammonium Chloride 4. Naphthalene (Moth ball)
  30.  Sublimation • Occurs because particle at the surface have enough energy to break off from the solid and become gas SOLID GAS Solid iodine Iodine vapour A substance sublimes because the forces between the particles in the liquid state are too weak to remain in this state.
  31. Summary Mixture of Solid & Liquid Mixture of Liquid & Gas SOLID LIQUID GAS MELTING POINT BOILING POINT
  32.  Summary Heat Absorbed (endothermic) Heat given out (Exothermic) Process involved Melting Boiling Evaporation Sublimation Freezing Condensation

Via Slideshare.com


Comments

Post a Comment