6 4/7/11 – “C” DayObjective: To understand the relationships between pressure, temperature, and kinetic energy.Do Now: Sketch a graph showing the relationship between Temperature and Kinetic Energy of Particles. Where would you place a solid, liquid and a gas on this graph?Today:Complete Test CorrectionsComplete Phet States of Matter ActivityIntermolecular Forces - HW
7 4/8/11 – “D” DayObjective: To understand the relationships between pressure, temperature, and kinetic energy.Do Now: In our Weblab – Why did some particles stick together and others not? What do you think this did to the temperature needed to turn from a solid liquid or liquid gas?Today:Collect Intermolecular Forces – HWDiscuss Phet States of Matter ActivityStates of Matter NotesGases Lab
8 Kinetic theory and phases of matter Kinetic theory – all matter is made up of tiny particles that are constantly in motion. Remember kinetic = motionEnergy is Directly Related to TemperatureRemember q (heat or energy) = mcΔT
9 What determines if something is a solid, liquid or gas? TemperaturePressureIntermolecular Forces
10 Temperature Average KE per molecule in a substance. Measure w/ thermometer. Alcohol in thermometer expands as it is heated.Units:FahrenheitCelsiusKelvin
11 TemperatureTemperature is related to the random motion of atoms & molecules in a substance.(Molecules will refer to : atoms & molecules)↑ Temp = ↑ average KE of molecules↓ Temp = ↓ average KE of molecules
12 TemperatureQ: Consider 1L vs 2L of boiling water. Which has a higher temperature?A: Same temp. Average KE of molecules is the same.
13 Absolute Zero Temp has no upper limit. Stars (plasma): MANY MILLION °C Absolute Zero- Nature’s lowest possible temperature.0 Kelvin = -273 ° CMolecules lost all available KE. No motionNo more E can be removed…. Can’t get any colder than this!
15 Heat and temperatureHeat- the thermal energy transferred from one substance to another due to a temperature difference (Av. KE) between the molecules of two substances.
16 Heat and TemperatureTemperature is the average kinetic energy in a systemHeat is the transfer of energy between objects because of the difference in temperatureHeat transfers spontaneously from hot to cold
17 Which has the higher temperature, 1 L or 2 L of boiling water? Which has more energy?
18 Intermolecular Forces Attraction between particlesIonic bondsHydrogen bondsVan der waal’s forces
19 Ionic bondsIonic compounds are not arranged in molecules, but instead form large crystals held togetherby ionic bonds.Charge on ionsprovidesattraction.
20 Hydrogen bondsCovalent molecules form solids when intermolecular forces are great enough to hold molecules together, usually as a crystal.Strongest intermolecular force is hydrogen bonding, between the H of one molecule, and an N, O or F of another. These molecules are very polar and have strong + and - ends
21 Water – example of H bonds The dashed lines are the hydrogen bonds in an ice crystal
22 Van der waal’s forcesOther molecules are attracted by weaker dipole and London dispersion forces. These forces are also between positive and negative ends of a molecule, but the charges are usually much smaller than in hydrogen bonds.
28 Liquids and Kinetic Theory Liquids have three properties that relate to the Kinetic Theory:EvaporationVapor pressureBoiling point
29 EvaporationRemember, temperature is a measure of the average kinetic energy.Some particles have more kinetic energyParticles with a high enough kinetic energy can break free from the surface and become a gas
30 Vapor PressureIn a closed system, molecules move back and forth between liquid and gas.
31 Vapor pressureThe vapor pressure is a measure of how much gas there is at a given temperature.The higher thetemperature, thehigher the vaporpressure
32 Boiling pointBoiling occurs at specific temperatures and pressures. Pockets of gas form in the liquid as bubbles and move to the surface.
33 Boiling pointWhen the vapor pressure equals the atmospheric pressure the liquid boils
34 Changes of state Solid to liquid – melting Liquid to solid – freezing Liquid to gas – evaporationGas to liquid – condensationSolid to gas - sublimation
35 Construct a heating curve for water Heating curve lab
36 Heating curveWhat is happening between B and C?
37 Heat of Fusion Energy required to go from a solid to a liquid at the same temperature.Between B and C, energy is being used to melt the material
38 Heat of Fusion 100/18 = 5.6 moles 5.6 moles *6.01kJ/1 mole = 33.66 kJ How many Joules are required to melt 100 g of ice at 0°C? Heat of fusion for water is 6.01kJ/moleHow many moles of water is 100g?100/18 = 5.6 moles5.6 moles *6.01kJ/1 mole = kJ
40 Heat of vaporization Energy required to go from a liquid to a solid at the same temperature.Between D and E, energy is being used to evaporate (boil) the material
41 Heat of vaporization 150/18 = 8.3 moles How many Joules are required to convert 150 g of water at 100°C to steam? Heat of vaporization for water is 40.67kJ/moleHow many moles of water is 150g?150/18 = 8.3 moles8.3 moles *40.67kJ/1 mole = kJ
42 SublimationUnder certain conditions, a material can go directly from a solid to a gas. This is called sublimation.Air freshener mini lab