Monday, September 28, 2009

Chemistry: Chapter 1 - Kinetic Particle Theory

1.1 States of Matter
a) Matter is a substance that has mass and occupies space.
b) 3 forms of matter:
  1. Solid
  2. Liquid
  3. Gas
1.2 Kinetic Particle Theory
a) Solid state:
  1. Orderly, closely packed arrangement.
  2. Very strong attractive force between particles.
  3. Very low kinetic energy of particles.
  4. Particles vibrate and rotate about a fixed position.
b) Liquid state:
  1. Disorderly, less closely packed than in a solid arrangement.
  2. Strong attractive force between particles.
  3. Low kinetic energy of particles.
  4. Particles slide over each other.
c) Gaseous state:
  1. Disorderly, very far apart arrangement.
  2. Very weak attractive force between particles.
  3. High kinetic energy of particles.
  4. Particles move about at a great speed.
1.3 Changes of State and the Kinetic Particle Theory
  1. Melting
  2. Freezing
  3. Boiling
  4. Evaporation
  5. Condensation
  6. Sublimation
1. Melting (Solid to Liquid)
a)Solid --------------------------------b)--------------------------------c)Liquid
a) Heat energy that is absorbed is converted to kinetic energy which cause the praticles to vibrate faster about their fixed positions.
b) Particles begin to break away from their fixed positions as they gain enough vibration to overcome the attractive forces between them. (Temperature remains constant throughout that period)
c) Particles are no longer in their fixed positions. They slide over one another. Substance is now a liquid.

2. Freezing (Liquid to Solid)
a)Liquid --------------------------------b)--------------------------------c)Solid
a) Particles give out energy which decreases their kinetic energy and they began to move slowly.
b) Particles no longer have energy to move about which cause them to settle into fixed positions. (Temperature remains the same throughout the period)
c) Particles settle into fixed position and can only vibrate about in their fixed positions. Substance is now a solid.

3. Boiling (Liquid to Gas)
a)Liquid ------------------------------------------------------------------b)Gas
a) Through heating, energy is absorbed and kinetic energy increases causes the particles in a liquid to move faster.
b) Eventually, the particles have enough energy to overcome the forces that is holding them together. Particles can now spread far apart in all directions. Substance is now a gas.
*Temperature remains constant during the boiling process.*

4. Evaporation (Liquid to Gas at a lower boiling point)
a) Evaporation occurs because some particles have enough energy to escape as a gas from the surface of the liquid.

5. Condensation (Gas to Liquid)
a) Condensation occurs because gas particles that evaporate loses energy and move more slowly. Movement of parrticles becomes slow enough for the gas to change into a liquid.

6. Sublimation (Solid to Gas)
a)Sublimation occurs because particles at the surface of the solid have enough energy to break away from the solid and escape as a gas. Example: Dry ice

*Heat absorbed causes particles to move faster. OR Heat given out causes particles to move slower.

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