Heat & Energy. It s a phase changer!!

Transcription

1 Heat & Energy It s a phase changer!!

2 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

3 Language Objectictives You will identify the factors that cause systems to gain or lose energy (heat) as part of a class discussion. You will integrate how Le Chatelier and the kinetic molecular theory relate to phase changes in a graphic organizer in small groups. You will illustrate how molecules move in the different states of matter in the form of a comic in small groups.

4 What causes matter to change states/phases?

5 Le Chatlier s Principle A system at equilibrium that is subjected to STRESS will react in a way to RELIEVE that STRESS. In the case of phases(solid, liquid, gas) it causes them to change.

6 Changes in the system Three types of stress: STRESS Concentration (number of particles) Temperature (heating or cooling) Pressure (increasing or decreasing) essentialchemistry/flash/lechv17.swf

7 Results of STRESS Changes in the direction of the reaction Changes in the state of matter (solid, liquid or gas) Change the moles of gas either increasing or decreasing the amount of gas produced.

8 Kinetic-Molecular Theory Yet another thing that dictates phase. Particles in motion are ALWAYS in motion.

9 Do You Remember: Kinetic Energy The energy of MOTION. Potential Energy The energy and object possess when it is AT REST

10 Phase change Solid Liquid Gas Low K.E. High K.E. (kinetic energy) fr1.1.html - nealgaslaw/fr1.1.html

11 Going from a Solid to Liquid state You either: Melt = go from a solid to a liquid Or Freeze = go from a liquid to a solid m.p.= melting point Melting point of water = 0 C

12 Going from a Liquid to a Gas You either: Vaporize= going from liquid to gas Or Condense=going from a gas to a liquid b.p.=boiling point b.p. of water = 100 C

13 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

14 Language Objectictives You will identify the factors that cause systems to gain or lose energy (heat) as part of a class discussion. You will integrate how Le Chatelier and the kinetic molecular theory relate to phase changes in a graphic organizer in small groups. You will illustrate how molecules move in the different states of matter in the form of a comic in small groups.

15 Exit ticket Draw or explain how molecules move in the three states of matter.

16 Energy Transfer Heat Energy (Q) can be used to: CHANGE temperature OR CHANGE phase BUT never both at once

17 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

18 Language Objective You will record information from a powerpoint illustrating phase/energy/heat transfer as they relate to phase changes in a note packet. You will calculate the amount of heat lost or gained through various scenarios individually and in pairs.

19 Energy Conservation Q (lost) = Q (gained) So if something is losing heat something else is gaining heat

20 Other key vocab and Q = Heat = Joules (J) m = mass (in grams) symbols c = specific heat capacity (constant) different for EVERY element and compound Δ T= change in temperature (T 2 -T 1 ) H f = heat of fusion = energy needed to melt H v = heat of vaporization = energy needed to boil

21 Heat Curve waterphases/status_water.htm

22 Heat curve for water

23 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

24 Language Objective You will record information from a powerpoint illustrating phase/energy/heat transfer as they relate to phase changes in a note packet. You will calculate the amount of heat lost or gained through various scenarios individually and in pairs.

25 Exit Ticket On a separate sheet of paper sketch and label the heat curve for water.

26 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

27 Language Objective You will compare the two types of phase change diagrams and identify the similarities using a computer simulation in pairs and by writing it on a blank graphs. You will summarize how triple point and critical point are important to determine when matter can change phase using a computer simulation in pairs and by writing it on a blank graphs..

28 Heat Curves vs Phase Get a laptop Change Log in: PCHSlaptop, PClabtopsHS With a partners go to the following web site: Chemistry/gilbert/tutorials/interface.asp? chapter=chapter_11&folder=heating_curves Do the activity and answer the questions along the way in the handout provided.

29 Phase Change Diagram for Water Triple Point: the point where pressure and temperature of a substance allows the three phases (solid, liquid, gas) coexist in thermodynamic equilibrium in Critical Point/State: specifies the conditions (temperature and pressure) at which a phase boundary ceases to exist

30 Phase Change for CO2

31 Compare the two Water CO 2

32 Content Objectives Chemistry students wbat explain that energy lost equals energy gained in a system. Chemistry students wbat illustrate how the kinetic molecular theory relates to phase changes.

33 Language Objective You will compare the two types of phase change diagrams and identify the similarities using a computer simulation in pairs and by writing it on a blank graphs. You will summarize how triple point and critical point are important to determine when matter can change phase using a computer simulation in pairs and by writing it on a blank graphs.

34 Exit Ticke On a separate sheet of paper Explain how triple point is different from critical point.