# states of matter and thermodynamics. solid does not flow. definite shape. definite volume

Post on 26-Mar-2015

215 views

Category:

## Documents

Tags:

• #### dipoledipole slide

Embed Size (px)

TRANSCRIPT

• Slide 1

States of matter and thermodynamics Slide 2 Solid Does not flow. Definite shape. Definite volume. Slide 3 Liquid It flows. Takes on the shape of its container. Has a definite volume. Slide 4 Gas It flows. Takes on the shape of its container Has NO definite volume. Always fills the container its in. Slide 5 pHet States of Matter Lab Slide 6 4/7/11 C Day Objective: 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: 1.Complete Test Corrections 2.Complete Phet States of Matter Activity 3.Intermolecular Forces - HW Slide 7 4/8/11 D Day Objective: 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: 1.Collect Intermolecular Forces HW 2.Discuss Phet States of Matter Activity 3.States of Matter Notes 4.Gases Lab Slide 8 Kinetic theory and phases of matter Kinetic theory all matter is made up of tiny particles that are constantly in motion. Remember kinetic = motion Energy is Directly Related to Temperature Remember q (heat or energy) = mcT Slide 9 What determines if something is a solid, liquid or gas? Temperature Pressure Intermolecular Forces Slide 10 Temperature Average KE per molecule in a substance. Measure w/ thermometer. Alcohol in thermometer expands as it is heated. Units: Fahrenheit Celsius Kelvin Slide 11 Temperature Temperature is related to the random motion of atoms & molecules in a substance. (Molecules will refer to : atoms & molecules) Temp = average KE of molecules Slide 12 Temperature Q: Consider 1L vs 2L of boiling water. Which has a higher temperature? A: Same temp. Average KE of molecules is the same. Slide 13 Absolute Zero Temp has no upper limit. Stars (plasma): MANY MILLION C Absolute Zero- Natures lowest possible temperature. 0 Kelvin = -273 C Molecules lost all available KE. No motion No more E can be removed. Cant get any colder than this! Slide 14 Slide 15 Heat and temperature Heat- the thermal energy transferred from one substance to another due to a temperature difference (Av. KE) between the molecules of two substances. Slide 16 Heat and Temperature Temperature is the average kinetic energy in a system Heat is the transfer of energy between objects because of the difference in temperature Heat transfers spontaneously from hot to cold Slide 17 Which has the higher temperature, 1 L or 2 L of boiling water? Which has more energy? Slide 18 Intermolecular Forces Attraction between particles Ionic bonds Hydrogen bonds Van der waals forces Slide 19 Ionic bonds Ionic compounds are not arranged in molecules, but instead form large crystals held together by ionic bonds. Charge on ions provides attraction. Slide 20 Hydrogen bonds Covalent 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 Slide 21 Water example of H bonds The dashed lines are the hydrogen bonds in an ice crystal Slide 22 Van der waals forces Other 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. Slide 23 Dipole-Dipole Slide 24 Solids Held together by intermolecular forces in highly organized patterns. Dense and incompressible Do not flow Slide 25 Liquids Intermolecular forces hold particles together, but particles are not locked in place. Can move freely through the liquid. This allows the liquid to flow, but keeps the volume constant. Slide 26 Gases Particles in constant rapid motion, independent of each other. Gases are not held together by intermolecular forces, do not have a constant shape or volume Slide 27 Slide 28 Liquids and Kinetic Theory Liquids have three properties that relate to the Kinetic Theory: 1. Evaporation 2. Vapor pressure 3. Boiling point Slide 29 Evaporation Remember, temperature is a measure of the average kinetic energy. Some particles have more kinetic energy Particles with a high enough kinetic energy can break free from the surface and become a gas Slide 30 Vapor Pressure In a closed system, molecules move back and forth between liquid and gas. Slide 31 Vapor pressure The vapor pressure is a measure of how much gas there is at a given temperature. The higher the temperature, the higher the vapor pressure Slide 32 Boiling point 1. Boiling occurs at specific temperatures and pressures. Pockets of gas form in the liquid as bubbles and move to the surface. Slide 33 Boiling point When the vapor pressure equals the atmospheric pressure the liquid boils Slide 34 Changes of state Solid to liquid melting Liquid to solid freezing Liquid to gas evaporation Gas to liquid condensation Solid to gas - sublimation Slide 35 Construct a heating curve for water Heating curve lab Slide 36 Heating curve What is happening between B and C? Slide 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 Slide 38 Heat of Fusion How many Joules are required to melt 100 g of ice at 0C? Heat of fusion for water is 6.01kJ/mole How many moles of water is 100g? 100/18 = 5.6 moles 5.6 moles *6.01kJ/1 mole = 33.66 kJ Slide 39 What is happening between D and E? Slide 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 Slide 41 Heat of vaporization How many Joules are required to convert 150 g of water at 100C to steam? Heat of vaporization for water is 40.67kJ/mole How many moles of water is 150g? 150/18 = 8.3 moles 8.3 moles *40.67kJ/1 mole = 338.9 kJ Slide 42 Sublimation Under certain conditions, a material can go directly from a solid to a gas. This is called sublimation. Air freshener mini lab Slide 43

Recommended