CHAPTER 22 AND 23

HEAT TRANSFER AND CHANGE OF PHASE

FLT :Given heat transfer problems and questions , I will be able to define, compare and contrastsolid, liquid, gas and plasma different processes of phase change conduction , convection and radiation high and low pressure conductors and insulators calculate heat absorbed and released during phase change and temperature change

HW p 351 Odd numbers Review Questionsp 352 #21- 25, Think and Solve p353 - #37

Monday:Solid , Liquid and Gas

Solid• Has definite shape• Has definite size or volume

Liquid• No definite shape • Has definite size or

volume

Gas• No definite shape • No definite volume or size

Particles Inside Matter

Write and share something about the following:AtomsDemocritus and his ideasDalton and his ideas about atomsMoleculesScanning Tunneling Microscope

Water Molecule (H2O)

Copper Molecules (Element)

Carbon Dioxide Molecule

Oxygen Gas Molecule(O2)

HW : Characteristic Properties

1. Hardness2. Melting Point3. Boiling Point4. Color5. Size6. Shape7. Shininess8. Malleability9. Ductility10. Conductivity to heat and electricity

Boiling Points and Melting Points

• Boiling Points

Water - 1000 CEthyl Alcohol– 78CMercury – 356.6 0C

• Melting Points

Aluminum – 6600 CLead - 327.40 CGold - 10630 CCopper - 10860 CIron - 15350 C

II. Vocabulary II1. Solid 2. Crystalline Solid 3. Amorphous Solid4. Liquid 5. Viscosity 6. Fluid7. Gas 8. Volume9. Temperature 10. Pressure

Amethyst is violet quartz crystal

Crystalline Solids

Salt Molecule

Amorphous Solid

Viscous LiquidsViscosity-

Water Molecule (H2O)

Alcohol C3H7OH

Viscous FluidThree-dimensional turbulent flow created by a wake vortex from a cropdusting aircraft.

(Image is taken from NASA's Web site: http://www.nasa.gov.)

Fluids-

Gas

Carbon Dioxide Molecule

Thursday:Physical & Chemical Changes

Physical Change • Alters the form of a substance but does not change it to another substance

Chemical Change • Changes into a different substance with

different properties

Energy

Thermal Energy • Energy from the

movement of its particles

Chemical Energy • Energy from the chemical

bonds of atoms within .

Law of Conservation of Energy

• Energy changes from one form to another but no energy

is lost

Thermal Energy

• Matter changes whenever energy is added or taken away

• When something is heated , it gains thermal energy

• When something is cooled , it loses thermal energy

Tuesday Temperature Conversion

Changes Between Liquid and Solid

1. Melting Heat is Absorbed - change in state from solid

to liquid - melting occurs at a

temperature called melting point

SOLID LIQUID Ice -00C= 320F

B. FreezingHeat is Released - the change of state from

liquid to solid - reverse of melting - occurs at a temperature

called freezing point LIQUID SOLID Freezing Point of water=

00C=320F

Changes between Liquid and Gas

3. Vaporization Heat is absorbed Liquid gains enough

energy to become gas

Liquid Gas

3a. Evaporation Vaporization that takes place

on the surface of the liquid Ex. Ocean

3B. Boiling Vaporization that takes place

inside a liquid Ex . Boiling water Boiling Pt of water = 1000C= 2120F

4. Condensation Heat is released - gas loses thermal energy to become liquid Ex. Clouds form when water vapor

condenses to water droplets suspended in air

GAS LIQUID Ex. Breath air onto a mirror ( cold surface) GAS LIQUID

Changes Between Solid and Gas

E. Sublimation Heat is absorbed - when the surface of a solid gains more energy to

become gas . - Particles do not pass liquid state at all SOLID GAS Ex. Solid air freshener ; dry ice(CO2)

CW:Conduction, Convection and Radiation p 325 Tree Map Definition, Drawing and Examples

CONDUCTION CONVECTION RADIATION

DEFINITION

DRAWING

EXAMPLES

Difference Conductors and Insulators p 337

CONDUCTORS INSULATORS

CHARACTERISTICS

EXAMPLES

Chapter 23P339 – 347

By two’s a.Processb.Definition change from ____to _____c.Kinetic energy ( increasing or decreasing)d. molecules are moving (less or more )e. Temperature is hotter or colderIndicate Temperature points of water f. Atmospheric Pressure is low or high g. humidity is ( less or more)h. heat energy (released or absorbed )

PROCESS

A CHANGE FROM ____TO _____

B.KINETIC ENERGY (increasing or decreasing)c.MOLECULES MOVING ____

D. HAPPENS WHEN TEMPERATURE IS

E. INCREASES/DECREASES ATM PRESSUREF.HUMIDITY BECOMES LESSOR MOREG.HEAT/THERMAL ENERGY RELEASED OR ABSORBED

Make a Flow chart for Refrigerator Cooling Cycle P 349Identify Parts – and what’s happening on that part of the Refrigerator :Groups use paper charts

Vocabulary:SaturatedRelative humidity Regelation

EQUATIONS:Q= mc ATQ= mL L= HEAT OF FUSION OR HEAT OF VAPORIZATION

L= Heat of fusion = The energy required to change a gram of a substance from the solid to the liquid state without changing its temperature is commonly called it's "heat of fusion".

Heat of vaporization the amount of heat required to convert unit mass of a liquid into the vapor without a change in temperature.

Questions p 348Questions p 349

Copy The Charts :A. specific heatB. latent heat table

Specific Heat Capacity Table

Substance Specific Heat Capacity

at 25oC in J/goCH2 gas 14.267He gas 5.300H2O(l) 4.184lithium 3.56ethyl alcohol 2.460

ethylene glycol 2.200

ice @ 0oC 2.010steam @ 100oC 2.010

vegetable oil 2.000

sodium 1.23air 1.020magnesium 1.020

aluminum 0.900Concrete 0.880glass 0.840potassium 0.75sulphur 0.73calcium 0.650iron 0.444nickel 0.440zinc 0.39copper 0.385brass 0.380sand 0.290silver 0.240tin 0.21lead 0.160mercury 0.14gold 0.129

Latent Heats TableSubstance(at 1 atm)Melting PointTm (K) Heat of FusionLf (cal/g) Boiling PointTb (K) Heat to VaporizeLv (cal/g)Hydrogen13.8 14.0 20.3 108Oxygen 54.4 3.3 90.2 50.9Nitrogen 63.3 6.1 77.3 48.0Ethyl Alcohol 156 24.9 351 205Mercury 234 2.7 630 70.0Water 273.15 79.7 373.15 539Lead 600 5.9 2023 208Aluminum 932 94.5 2740 2500Gold 1336 15.4 2933 377Copper 1359 32.0 1460 1210Iron 1808 69.1 3023 1520Tmelt = T freeze Tboil = T condense 1 cal/g = 4186 J/kg

Examples:1. Calculate the energy (in cal) absorbed by 10 grams of water that warms from 20 C to 90 C

2. Calculate the energy needed to melt 40 grams of 0C ice

3. Calculate the energy absorbed by 30 grams of 100 C water that is turned to 100 C steam

4. Calculate the energy released by 10 grams of 100C steam that condenses and then cools to 0C

Friday :Temperature, Volume and Pressure

Boyle’s Law

Boyle’s Law

Charles’ Law p 478

Problem Solving Activities:

2. 250 mL of Oxygen is collected at 27oC. What will be the volume of the gas at 35C at constant pressure?

Change the Temperature to K

2. The volume of a sample of gas is 650 mL at a pressure of 1.6 atmosphere. Assume that the temperature is held constant

a.) what is the volume of the sample at pressure of 2 atmosphere?

b.) what is the pressure of the sample when the volume is 1000 mL?

c.) what is the pressure of the sample when the volume is 500mL?

3. The volume of the sample of gas is 1.65 L at a pressure of 0.650 atmosphere. Assume that the temperature is held constant ,

a.) what is the volume of the sample at a pressure of 0.5 atmosphere?

b.) what is the pressure of the sample when the volume is 1 L?

c.) what is the pressure of the sample when the volume is 2.75 L?

4. The volume of a sample of gas at 50C is 2.5 L. Assume the pressure is held constant.

a.) What is the volume of the gas at – 10 C? b.) At what temperature in C would be 1.25 L ? c.) At what temperature ( in C) would be 2.75

L?

Experiment :It’s a Gas

Purpose : To determine how the volume of the gas change as the pressure on it increases.

Materials :• Syringe• 4 books of equal weight Procedure :• Lift up the plunger as high without going off scale. The volume of the gas inside

will be equal to 60 cc.• Seal the opening with a cap or clay.• Hold the syringe upright with the cap at the bottom.• Place a single book at the top of the plunger . Balance the book carefully so

that it does not fall.• Read the volume of the plunger and record it in the data table.• Place another book on top of the first book and read , then record the new

volume.• Repeat step 6 for the 2 succeeding books.• Remove books one at a time. Record the new volume .

• IV. Data Table • Adding Books Removing Books • Number of booksVolume in ccNumber of BooksVolume in cc0 book4

books1 books3 books2 books2 books3 books1 book4 books0 book• V. Graph• VI. Analysis and Conclusion • Did the volume change between the addition of the 1st and the 2nd book?

_______• Did it change with the same amount ? _______• Did the volume change between the addition of the 2nd and the 3rd book?

_______• What happens as you increase the number of books on the volume of the

air inside the syringe?_____________________________________________

• What is happening to the gas particles in air that could explain this behavior?