Kinetic Molecular Theory (con t) Kinetic Molecular Theory Gas Liquid Solid 1. Slightly 2. High 3. Does not expand to

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1 Kinetic Energy and (Kelvin) Temperature Temperature is a Kinetic Energy and (Kelvin) Temperature(2) The Kelvin temperature scale is called the Absolute Zero - Zero degrees on the 1. Highly 2. Low 3. Fills 4. Assumes the 5. Rapid 6. Expands Kinetic Molecular Theory Gas Liquid Solid 1. Slightly 2. High 3. Does not expand to 4. Assumes the 5. Slow 6. Low expansion 1. Slightly 2. High 3. Rigidly 4. Retains own 5. Extremely Slow 6. Low expansion Kinetic Molecular Theory (con t) Gases Liquids Solids 1. Particles are 1. Particles are close 1. Particles very close 2. Particles are in 2. Particles are in constant 2. Particles can only The Kinetic-Molecular Theory states that the strength of the attraction between molecules 3. Weakest or 3. Medium attraction 3. Strong attraction Liquids and Solids are considered by some scientists to be one phase of matter called the Intermolecular Forces Intra Inter Intramolecular Forces Within Intermolecular Forces Between Hydrogen Bonds Are specialized dipole-dipole interactions between the partial positive The large electronegativity difference between the atoms Dipole-Dipole - caused by the attraction between the H-bonds are the strongest of the 1

2 Liquids - Changes of State Evaporation or Vaporization - Conversion of a liquid Liquids - Changes of State #2 Heating increases the rate of At a certain temperature most of the molecules in a liquid do not have enough Evaporation is a cooling process because the particles that have the In an open container, molecules that Open Container Dynamic Equilibrium #1 In a closed container, initially, when there is only liquid some of the particles Dynamic Equilibrium #2 Phase Change and other Misc. When a liquid boils the escaping particles are those with the highest These vapor particles create a pressure by colliding with the walls of the container. This pressure is called equilibrium vapor pressure. Sublimation - Going directly from the Deposition - Going directly from the Amorphous Solids - have no 2

3 Phase Change and other Misc. Heat of Fusion - Amount of heat required to Heating Curve Heat of Vaporization - Amount of energy required to change one g of a Temp. ( C) Heat Added Phase Diagrams Energy - Is the Thermochemistry (part 1) Energy comes in many forms: Heat Energy - Can never be completely used to do In most processes, chemical or physical, energy is Water Critical Temp Unit of energy SI Unit of energy calorie - The amount of energy required to Specific Heat Capacity Specific Heat - The amount of energy required to Specific Heat Capacity (C) - The amount of energy required to Dietary Calorie = 1000 energy calories Endothermic changes - When substances Unit of specific heat capacity = Exothermic changes - When substances Calorimeter - A device used to 3

4 Sample Problem #1 An apple can provide of heat energy. What mass of water could this amount of energy raise from the freezing point (0.00 C) to the ΔT = q = m x ΔT x C Sample Problem #2 What is the mass of a silver ring if its temperature changes from when it absorbs of heat energy? Specific Heat Capacity of Silver = cal/(g x C) ΔT = Sample Problem #3 The temperature of a piece of copper with a mass of changes from when the metal absorbs 849 J of energy. What is the specific heat capacity of copper? Viscosity The friction between molecules or how easily if flows. The stronger the Ethanol Water Glycerol! Surface Tension Molecules in the middle of a liquid interact equally with the molecules in all directions. However, particles on the surface are pulled Water : A unique liquid 1. Water is a liquid at room temperature, instead of a 2. Water has a high heat capacity. Therefore, it can absorb and release 3. Ice has a lower density than liquid water. This is why ice 4. Water has a high surface tension. Important in 5. High heat of 6. Good solvent - polar nature of water allows it to 4

5 Solids Crystalline Solids Particles that make up these solids are packed in a regular highly ordered structure called A solution is a What is a Solution? Solutions do not need to be liquid, they can be Metallic Solids Consist of fixed Good conductors of electricity because the valence electrons are free to move. Also good conductors of heat as well as being malleable and ductile. Examples: Air, Soda, Gatorade, Tap Water, steel, bronze, jewlery Solution Formation The interactions of solute dissolving in a solvent is called Solvation Video Clips The component present in the greatest amount in a mixture is called the The RATE of dissolving, not the total amount of solute dissolved can be The RATE of dissolving, as well as the Solubility Solubility is the amount of solute that can be Unsaturated More solute can be Saturated Contain the maximum amount of Supersaturated Supersaturated contains more solute than would normally be A supersaturated solution is clear before a In a saturated solution, the rate of 5

6 Supersaturated #2 Miscible vs. Immiscible Miscible When there is no APPARENT limit of the Solutions that are miscible tend to have Immiscible Liquids that do not dissolve Crystals begin to form in the solution immediately after the addition of a seed crystal. Excess solute crystallizes rapidly. Factors Affecting Solubility Solubility changes with Factors Affecting Solubility #2 Gases decrease their solubility in liquids with Gases increase their solubility in liquids with Henry s Law At a given temperature the solubility of a gas in a liquid is directly proportional to the 6