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Phases of Matter and Solutions

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Presentation on theme: "Phases of Matter and Solutions"— Presentation transcript:

1 Phases of Matter and Solutions
Mr. Nylen Chemistry

2 Review of Calorimetry

3 Worksheet – Reviewing what we know
Use worksheet to help you review Solids Liquids Gases For help look to: Review book – page 45 Text page 6-7 – Solids, liquids, and gases are states of matter Pages – Properties of gases Page 443 – Paragraph next to brown bottle

4 Comparison of phases at the molecular level (p. 1)
Solids Liquids Gases

5 Comparison of Phases (p. 1-2)
Property Solid Liquid Gas Orderliness Particle Movement Interparticle distances Density Interparticle forces of attraction

6 Comparison of Phases (p. 1-2)
Property Solid Liquid Gas Interparticle Forces of Attraction Kinetic Energy of Particles Diffusion Rates Compressibility Shape Volume

7 Additional Physical Properties
Solids – usually have a crystalline structures Regular repeating geometric arrangement of atoms Liquids – Exhibit unique properties such as: volatility (ability to evaporate) Viscosity (resistance to flowing) Surface tension (ability of particles to hold together) As the forces of attraction between particles in a liquid increase, the volatility decreases, the viscosity increases, and the surface tension increases

8 Amorphous Solids Super cooled liquids –
Liquids that appear to be solid but yet they do flow slowly over time when force is applied. They have no observable crystalline structure. Examples include some plastics, rubber, butter, and amorphous sulfur.

9 Viscosity of amorphous solids
The viscosity (resistance to flow) of amorphous materials increases with decreasing temperature and decreases with increasing temperature Vegetable oil is too think to run in cars, so you have to heat it before you burn it

10 Phase Changes and Energy
Phase change diagram Absorb energy, endothermic Solid Liquid Gas Release energy, exothermic

11 Heat of Fusion Amount of heat absorbed when 1g of a substance melts at its melting point Same amount of heat as heat of crystallization Heat of fusion = heat needed to melt a fused solid Heat of crystallization = heat needed to fuse together a liquid 1 gram 1 gram water

12 Heat of Fusion Units = Joules/gram Formula: Hf equals heat of fusion
Look up Hf values in reference tables B Waters is 334 J/g

13 Heat of Vaporization Amount of heat absorbed when 1g of a substance vaporizes at its boiling point Same amount of heat as heat of condensation

14 Heat of vaporization Units: Formula
Joules/gram Formula Look up heats of vaporization on table B Waters is 2260 J/gram

15 Heat causing temperature change
Remember that we can calculate the amount of heat needed to change the temperature of a certain mass of water Where c is the specific heat of water (4.18) T is temperature change Mass is mass of water

16 Tricks When approaching problems, figure out if the substance is fusing (melting/freezing), vaporizing (boiling/condensing), or just changing temperature Look up the corresponding value on the reference table and use the correct formula

17 Practice Problems RB pg. 65, 30-46

18 Lab – Heat of Fusion of Ice
Calorimetry

19

20 Problem Set (and Turn in Lab)
Complete the following: Show phase changes, endo, and exo Solid Liquid Gas

21 Review: When approaching problems, figure out if the substance is fusing (melting/freezing), vaporizing (boiling/condensing), or just changing temperature Look up the corresponding value on the reference table and use the correct formula

22 Problem Set (until 12:35) How much heat is needed to completely melt gram of ice at 0 celcius, heat it to 100 celcius, and completely boil it? Step 1 (melt it) Step 2 (heat it) Step 3 (boil it

23 Heating Curves – pg. 8 Calculations:
Heating from solid phase at 100 J/min

24 Heating Curves and Energy
Heating from solid phase at 100 J/min PE KE (Temp) AB BC CD DE

25 Notes – page 10 together

26 Cooling Curve PE KE (Temp) AB BC CD DE

27 Notes pg. 11

28 Try on your own

29 HW – review book pg. 60 #1-16 Some we’ve already done before

30 Lab – Heat of crystallization of Wax

31 HW – Due Tuesday Pg notes

32 Review Homework Go over page in notes

33 Notes pg. 15-16 A heating curve is given Create your own cooling curve
Determine the KE and PE for each interval Remember, if KE increases, PE stays the same Create your own cooling curve We will be doing this again in the lab

34 Energy, and Heating Curves

35 Lab – Cooling Curve for Lauric Acid

36 Homework Finish Lab RB pg. 47, 1-16

37 Review Homework Go over RB pg. 47, 1-16 Go over Lauric Acid Lab

38 Notes p. 17 Work through pg

39 Notes p. 19-20 Work in your lab groups to complete these questions
Put answers on separate sheet of paper and hand in with all group members’ names

40 Review – Pg Go over in class

41 Equilibrium Vapor Pressure – Notes p. 23
Defined: Vapor pressure is pressure exerted on the surface of a liquid or solid by particles of the substance that have changed over to vapor phase As more particles are converted to vapor, vapor phase increases, vapor pressure increases

42

43 Relationship between vapor pressure and Boiling point
Boiling – bubbles of vapor form under surface then rise to the top as liquid turns to a gas In order to boil vapor pressure in bubble Has to be equal to the air pressure outside If pressure outside is greater bubble will collapse

44 Questions: As the pressure on the surface of a liquid decreases, the temperature at which the liquid will boil will A. Increase B. Decrease C. Remain the same The vapor pressure of a liquid is .95 atm at 600C. The normal boiling point of the substance could be 200C C C C

45 Notes p. 24 P. 24 together P. 25 on your own

46 Review IMF – complete study guide p. 27

47 Intermolecular Forces of Attraction
Dipole-Dipole Attraction: Dipole = polar molecule Dipole = 2 poles, like a magnet

48 Hydrogen Bonding Very Very Very strong dipole-dipole attraction
Occurs between molecules that contain hydrogen bonded to small, highly electronegative elements (F, O, N)

49 Van der Waals Forces (Dispersion Forces)
In all molecules electrons are constantly moving At any given instant in time MORE could end up on one side of the molecule than the other

50 Van der Waals forces This is the ONLY force of attraction that exists between nonpolar molecules The more electrons, the stronger the Van der Waals forces Ex: F2, Cl2, Br2, I2 gas gas liquid solid

51 Notes p. 27 together

52 Posters! Create a poster on one of the following:
Amorphous Solids Phase Change Diagram Heat of Fusion Heat of Vaporization Cooling Curves Heating Curves Follow the Rubric for your topic, your whole group will receive the same grade.

53 Finish notes p. 28 and 29 homework


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