chemistry unit 2 pp.pptx [repaired]
TRANSCRIPT
This is a unit of study called “Matter and Energy”… …in which basic properties of matter and energy transformations are discussed.
Slides that utilize media are:
…Slide 52 has video on demand that can be viewed online at any time for students.
…slide 69 has sound to correspond to blocks falling in water. Slide is animated so students can visual what is happening. A transparent overlay covers the block of wood and ice. As a teacher I point out that the wood is 25% submerged as it has a specific gravity of 0.25 while the ice is submerged 90% as it has a specific gravity of 0.90. I then show this actual demonstration to students using a document camera.
…slide 71 has sound to correspond to cloud of CO2 falling in down stairs because it is denser than air. A voice explanation is also included to give a brief explanation.
… slide 202-207 demonstrate the theory and show chromatography by animated clicks on PowerPoint I would give a verbal explanation in class to explain the slides.
… slide 227-231 concern electrolysis slides 230 and 231 have an embedded video I that plays when clicked. Video came from PBS tv show. A voice explanation is also included to give a brief explanation
…slide 238-261 explain properties of matter. A slide 238 and 241 have video to give additional information
…Slide 255 are a series of jpeg images I captured from video I shot to sequence as a slide that looks like video.Slide 256 has the actual video of class demonstration I recorded. It plays regular speed and slow motion. Each was created using Windows Movie Maker.
…slide 261 has an external link to an animation by a textbook author (bottom right corner)
…Many slides have additional links to additional information (e.g. slide 8 (mouse over the word “matches “to get more information from Wikipedia)
www.unit5.org/chemistry
Energy and Matter
Unit 2
Guiding QuestionsWhy do substances boil or freeze at different temperatures? Why do we put salt on the roads in the winter?
Why does sweating cool us?
What is energy?
How do we measure energy?
Table of Contents‘Matter and Energy’
(13) Introduction - Bonding(14) Temperature vs. Heat(11) Density (6) Carbon Dioxide & Monoxide (4) Archimede’s Principle (3) Galilean Thermometer(11) Golf Ball Lab(15) Solid, Liquid, and Gas (3) Heating Curve(13) Classification of Matter (6) Crystalline Structure(10) Allotropes
(9) Alloys(4) Separation Techniques(11) Distillation(2) Centrifugation(3) Electrolysis(5) Properties of Matter(6) Energy(11) Exothermic vs. Endothermic(29) Calorimetry(12) Nuclear Energy
Lecture Outline – Energy and Matter
KeysKeys
Lecture Outline – Energy and Matter
Lecture Outline – Energy and Matter
student notes outline
textbook questions
http://www.unit5.org/chemistry/Matter.html
textbook questions
text
Chemistry of Matches
P4S3 + KClO3 P2O5 + KCl + SO2
tetraphosphorustrisulfide
potassiumchlorate
diphosphoruspentaoxide
potassiumchloride
sulfurdioxide
D
The substances P4S3 and KClO3 are both present on the tip of a strike anywhere match. When the match is struck on a rough surface, the two chemicals (reactants) ignite and produce a flame.
Charles H.Corwin, Introductory Chemistry 2005, page 182
Safety matches
The products from this reaction are P2O5, KCl, and SO2,the last of which is responsible for the characteristic sulfur smell.
Strike anywhere matches
The substances P4S3 and KClO3 are separated. The P4S3 is onthe matchbox cover. Only when the chemicals combine do they react and produce a flame.
block of wood: length = 2.0 m width = 0.9 m height = 0.5 m
block of wood: force = 45 N
2.205 pounds = 1 kilogram 10 Newton (9.8 N)
Force versus Pressure
Area = 0.9 m x 2.0 m = 1.8 m2
Area = 0.5 m x 2.0 m = 1.0 m2
Area = 0.5 m x 0.9 m = 0.45 m2
area
force Pressure
2m 1.8
N 45.0 Pressure
2m 1.00
N 45.0 Pressure
2m 0.45
N 45.0 Pressure
block of wood: length = 2.0 m width = 0.9 m height = 0.5 m
25 N/m2 45 N/m2 100 N/m2
Herron, Frank, Sarquis, Sarquis, Schrader, Kulka, Chemistry, Heath Publishing,1996, page Section 6.1
Pressure
area
forcepressure
Which shoes create the most pressure?
During a“physical change”
a substance changes some physical property…
During a“physical change”
a substance changes some physical property…
H2O
…but it is still the same material with the same chemical composition.
…but it is still the same material with the same chemical composition.
H2Ogas
solid
liquid
Chemical Property:Chemical Property:
The tendency of a substance to change into another
substance.
The tendency of a substance to change into another
substance.
caused by iron (Fe) reacting with oxygen (O2) to produce rust (Fe2O3)
Steel rusting:
4 Fe + 3 O2 2 Fe2O3
Chemical Change:Chemical Change:
Any change involving a rearrangement of atoms.Any change involving a
rearrangement of atoms.
Chemical Reaction:Chemical Reaction:
The process of a chemical change...The process of a
chemical change...
During a“chemical reaction”new materials are
formed by a change in the way atoms are bonded together.
During a“chemical reaction”new materials are
formed by a change in the way atoms are bonded together.
Physical and Chemical PropertiesExamples of Physical Properties
Boiling point Color Slipperiness Electrical conductivity
Melting point Taste Odor Dissolves in water
Shininess (luster) Softness Ductility Viscosity (resistance to flow)
Volatility Hardness Malleability Density (mass / volume ratio)
Examples of Chemical Properties
Burns in air Reacts with certain acids Decomposes when heated
Explodes Reacts with certain metals Reacts with certain nonmetals
Tarnishes Reacts with water Is toxic
Ralph A. Burns, Fundamentals of Chemistry 1999, page 23Chemical properties can ONLY be observed during a chemical reaction!
The formation of a mixture
The formation of a mixture
The formation of a compound
The formation of a compoundChemical Change
Chemical Change
Physical Change
Physical Change
Physical & Chemical Changes
Limestone,CaCO3
crushing
PHYSICALCHANGE
Crushed limestone,CaCO3
heating
CHEMICALCHANGE
Pyrex
CO2
CaO
Lime andcarbon dioxide,
CaO + CO2
Pyrex
O2
H2O
Pyrex
H2O2
Light hastens the decomposition of hydrogen peroxide, H2O2. The dark bottle in which hydrogen peroxide is usually storedkeeps out the light, thus protecting the H2O2 from decomposition.
Sunlight energy
H H
O O
Three Possible Types of Bonds
+ -
d+ d-
Covalent e.g. H2
Polar Covalent e.g. HCl
Ionic e.g. NaCl
Metallic Bonding
Metallic bonding is the attraction between positive ions and surrounding freely mobile electrons. Most metals contributemore than one mobile electron per atom.
“electron sea”e1-
e1-
e1-
e1-
e1-e1-
e1-
e1-
e1-e1-
e1-
e1-
e1-
e1-
e1-
e1-Free electrons
++
+
+
+
++
+
+
+
++
+
+
Cations
Bailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 245
Shattering an Ionic Crystal; Bending a Metal
Bailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 248
+ +
+++ ++
++++
+ +++
+
+
+++ ++
++++
+ +++
++ + + + ++ +
+ ++
+
+ + + ++ + ++
+ +
+++ ++
++++
+ +++
+
+
+++ ++
++++
+ +++
++ + + + ++ +
+ ++
+
+ + + ++ + ++
+-+ --- +
+- -+
- ++-+ -
-+
+ -+-- - -++
-+
+ - + - -+ + -
+-+ --- +
+- -+
- ++-+ -
-+
+ -+-- - -++
-+
+ - + - -+ + -
An ionic crystal
A metal
No electrostatic forces of repulsion – metal is deformed (malleable)
Electrostatic forces
of repulsion
Force
Force
broken crystal
Properties of Ionic Compounds
• Crystalline solids• Hard and brittle• High melting points• High boiling points• High heats of vaporization• High heats of fusion• Good conductors of electricity when molten• Poor conductors of heat and electricity when
solid• Many are soluble in water
Chemical Bonds
Increasing ionic character
Covalent bonding
Electrons are sharedequally
Cl Cl
Polar covalent bonding
Electrons are sharedunequally
ClH
Ionic bonding
Electrons are transferred
Cl1-Na1+
Ralph A. Burns, Fundamentals of Chemistry 1999, page 229
• between two identical nonmetal atoms are non-polar covalent.• between two different nonmetal atoms are polar covalent.• between nonmetals and reactive metals are primarily ionic.
Chemical Bonds
Increasing ionic character
Nonpolar covalent
Electrons are sharedequally
Cl Cl
Polar covalent
Electrons are sharedunequally
ClH
Ionic bonding
Electrons are transferred
Cl1-Na1+
Ralph A. Burns, Fundamentals of Chemistry 1999, page 229
• between two identical nonmetal atoms are nonpolar covalent.• between two different nonmetal atoms are polar covalent.• between nonmetals and reactive metals are primarily ionic.
Covalent vs. Ionic
Covalent
Transferelectrons
(ions formed)
+ / -
BetweenMetal andNonmetal
StrongBonds
(high melting point)
Shareelectrons
(polar vs. nonpolar)
BetweenTwo
Nonmetals
Weak Bonds
(low melting point)
Alike Different
Electronsare
involved
ChemicalBonds
Ionic
Different
Topic Topic
Photoelectric Generator
Solar Calculator
Radiant energy Evacuatedchamber
Metalsurface
Currentindicator
Positiveterminal
Voltagesource
cathode anode
Symbolic representationof a photoelectric cell
cathode anode
evacuated glassenvelope
Photoelectric Cell
Celsius & Kelvin Temperature Scales
Boiling pointof water
Freezing pointof water
Absolutezero
Celsius
100Celsiusdegrees
100oC
0oC
-273oC
Kelvin
100Kelvins
373 K
273 K
0 K
Temperature is Average Kinetic Energy
Fast Slow“HOT” “COLD”
Kinetic Energy (KE) = ½ m v 2
*Vector = gives direction and magnitude
Temperature Scales
Fahrenheit
212 oF
180 oF
32 oF
Celcius
100 oC
100 oC
0 oC
Kelvin
373 K
100 K
273 K
Boiling point of water
Freezing point of water
Notice that 1 kelvin degree = 1 degree Celcius
Kelvin Scale
blue
white
yellow
4300 K PIAA HID Bulb
5000 K PIAA Plasma Blue
5250 K Sunlight
4150 K PIAA Xtreme White
3800 K PIAA Super White
3200 K Halogen Bulb
2600 K Incandescent Bulb
Temperature Scales
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 136
Compare Celsius to Fahrenheit
oF – 32 = 1.8 oC
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 139
Converting 70 degrees Celsius to
Kelvin units.
oC + 273 = K
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 137
Temperature Scales
• Temperature can be subjective and so fixed scales had to be introduced.
• The boiling point and freezing point of water are two such points.• Celsius scale (oC)
– The Celsius scale divides the range from freezing to boiling into 100 divisions.
– Original scale had freezing as 100 and boiling as 0.– Today freezing is 0 oC and boiling is 100 oC.
• Fahrenheit scale (oF)• Mercury and alcohol thermometers rely on thermal expansion
Thermal Expansion
• Most objects e-x-p-a-n-d when heated• Large structures such as bridges must be
built to leave room for thermal expansion• All features expand together
COLDHOT
Cracks in sidewalk.
Equal Masses of Hot and Cold Water
Thin metal wall
Insulated box Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Water Molecules in Hot and Cold Water
Hot water Cold Water90 oC 10 oC
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Water Molecules in the same temperature water
Water(50 oC)
Water(50 oC)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Heat versus Temperature
Kinetic energy
Fra
ctio
ns o
f pa
rtic
les
lower temperature
higher temperature
TOTALKinetic ENERGY
= Heat
Molecular Velocities
speed
Fra
ctio
ns o
f pa
rtic
les many different molecular speeds
molecules sorted by speed
the Maxwell speed distribution
http://antoine.frostburg.edu/chem/senese/101/gases/slides/sld016.htm
Temperature vs. Heat
Measuredwith a
Calorimeter
TotalKineticEnergy
Joules(calories)
Measuredwith a
Thermometer
AverageKineticEnergy
oCelcius(or Kelvin)
Alike Different
A Propertyof
Matter
HaveKineticEnergy
Heat
Different
Topic Topic
Temperature
Conservation of Matter
Reactants yield Products
Heavy Metal Poisoning
Exposure to mercurymade the Hatter “mad”.
Eating chips of lead paint causes brain damage.
TREATMENT: Chelation therapy EDTA (ethylenediamine tetra acetic acid)
Arsenic treated lumber.‘Green-treated’ woodwill not rot outdoors for 50 years.
Density•
Density is an INTENSIVE property of matter.
- does NOT depend on quantity of matter. - color, melting point, boiling point, odor, density
• Contrast with
EXTENSIVE - depends on quantity of matter.- mass, volume, heat content (calories)
Styrofoam Brick
Properties of Matter
http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld001.htm
Pyrex Pyrex
ExtensiveProperties
IntensiveProperties
volume:mass:
density:temperature:
100 mL99.9347 g
0.999 g/mL20oC
15 mL14.9902 g
0.999 g/mL20oC
Styrofoam Brick
?It appears that the brick is ~40x more dense than the Styrofoam.
MMMM
VV= =DD
VVDD
BrickBrickStyrofoamStyrofoam
Styrofoam Brick
Which liquid has the highest density?
52
3
1
4
Coussement, DeSchepper, et al. , Brain Strains Power Puzzles 2002, page 16
least dense 1 < 3 < 5 < 2 < 4 most dense
Cube Representations
1 m3 = 1 000 000 cm3
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 119
Volume and DensityRelationship Between Volume and Density for Identical Masses of Common Substances
Cube of substance Mass Volume Density Substance (face shown actual size) (g) (cm3) (g/cm3)
Lithium
Water
Aluminum
Lead
10 19 0.53
10 10 1.0
10 3.7 2.7
10 0.58 11.4
Density
D
M
Vensity
ass
olume
D = M V
M = D x V
V =M D
Volume
Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 41
6 cm
3 cm
2 cm
1 cm
4 cm4 cm
2 cm
2 cm2 cm
Volume
Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 41
V = length x width x heightV = 2 cm x 2 cm x 2 cmV = 8 cm3
Volume = length x width x heightVolume = 6 cm x 2 cm x 3 cm
6 cm
3 cm
2 cm
1 cm
4 cm
Volume = 36 cm3
Volume =
Volume = 28 cm3
36 cm3
8 cm3
-
Density of Some Common Substances
Density of Some Common Substance
Substance Density (g / cm3)
Air 0.0013* Lithium 0.53 Ice 0.917 Water 1.00 Aluminum 2.70 Iron 7.86 Lead 11.4 Gold 19.3
Density of Some Common Substance
Substance Density (g / cm3)
Air 0.0013* Lithium 0.53 Ice 0.917 Water 1.00 Aluminum 2.70 Iron 7.86 Lead 11.4 Gold 19.3
*at 0oC and 1 atm pressure
Consider Equal Volumes
The more massive object(the gold cube) has the_________ density.
Equal volumes…
…but unequal masses
aluminum gold
GREATER
Density = Mass
Volume
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71
Consider Equal MassesEqual masses……but unequal volumes.
The object with the larger volume (aluminum cube) has the density.
aluminum
gold
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71
smaller
Christopherson Scales
Made in Normal, Illinois USA
Two ways of viewing density
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71
Equal volumes…
…but unequal masses
The more massive object(the gold cube) has thegreater density.
aluminum gold
(A)
Equal masses……but unequal volumes.
(B)
gold
aluminumThe object with the larger volume (aluminum cube) has the smaller density.
Carbon Dioxide Detector
• Where is the best location to place a CO2 detector in your home?
Recall: Density Air = 1.29 g/L
Density CO2 = 1.96 g/L
A. Top floor of homeB. Basement (near ceiling)C. Basement (near floor)D. It doesn’t matter, if your batteries are dead in the detectorC. Basement (near floor) Carbon dioxide is denser than air and sinks.
Symptoms of CO Poisoning
Concentration of COin air (ppm)*
Hemoglobin molecules as HbCO
Visible effects
100 for 1 hour or less 10% or less no visible symptoms
500 for 1 hour or less 20% mild to throbbing headache, some dizziness, impaired perception
500 for an extended period of time
30 - 50% headache, confusion, nausea, dizziness, muscular weakness, fainting
1000 for 1 hour or less 50 - 80% coma, convulsions, respiratory failure, death
*ppm is parts per million
Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 760
Carbon Monoxide Poisoning‘The Silent Killer’
Poisoning: Hb + CO HbCO
Hemoglobin (Hb) binds with carbon monoxide (CO) in the capillaries of the lungs.
If caught in time, giving pure oxygen (O2) revives victim of CO poisoning.Treatment causes carboxyhemoglobin (HbCO) to be converted slowly to oxyhemoglobin (HbO2).
Treatment: O2 + HbCO CO + HbO2
Carbon monoxide, CO, has almost 200 times the affinity to bind with hemoglobin, Hb, in the blood as does oxygen, O2.
Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 760
Exchange of Blood Gases
Tank of Water
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 143
Person Submerged in Water
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 143
Galilean Thermometer
• Density = Mass / Volume• Mass is constant• Volume changes with temperature
– Increase temperature larger volume
In the Galilean thermometer, the small glass bulbs are partly filled with a different (colored) liquid. Each is filled with a slightly different amount, ranging from lightest at the uppermost bulb to heaviest at the lowermost bulb. The clear liquid in which the bulbs are submerged is not water, but some inert hydrocarbon (probably chosen because its density varies with temperature more than that of water does).
Temp = 68 oC
Galilean Thermometer
In the Galilean thermometer, the small glass bulbs are partly filled with a different (colored) liquid. Each is filled with a slightly different amount, ranging from lightest at the uppermost bulb to heaviest at the lowermost bulb. The clear liquid in which the bulbs are submerged is not water, but some inert hydrocarbon (probably chosen because its density varies with temperature more than that of water does).
The correct temperature is the lowest floating bulb. As temperature increases, density of the clear medium decreases (and bulbs sink).
RECALL: Density equals mass / volume.
80o
76o
80o
76o
72o
64o
68o
64o
68o
72o
76oF 68 oF
Dissolving of Salt in Water
NaCl(s) + H2O Na+(aq) + Cl-(aq)
Cl-
ions
Na+
ions Water molecules
Determine the minimum amount of salt needed to make a golf ball float in 100 mL water.
Weigh out 50.0 g of NaCl
Trial Salt (g) Total Float /Sink
1 5.0 g 5.0 g Sink
2 5.0 g 10.0 g Sink
3 5.0 g 15.0 g Sink
4 5.0 g 20.0 g Sink
5 5.0 g 25.0 g Float
Add 5 g additions of salt to the water, dissolve, check to see if ball floats.
Continue with this method of successive additions until ball floats.
Re-weigh remaining salt and subtract this amount from 50.0 g to determinethe amount of salt needed.
Finally, repeat…begin 5 g less salt and add 1 g increments to narrow range.
Theorize, but Verify
Jaffe, New World of Chemistry, 1955, page 1
…We must trust in nothing but facts. These are presented to us by nature and cannot deceive. We ought in every instance to submit our reasoning to the test of experiment. It is especially necessary to guard against the extravagances of imagination which incline to step beyond the bounds of truth.
Antoine Laurent Lavoisier, 1743 - 1794
Theory Guides, Laboratory Decides!
Density of water = 1.0 g/mL
Need to determine density of a golf ball.mass =______ g (electronic balance)volume = ______ mL (water displacement method) or formula?
Density of golf ball cannot be made to decrease. Therefore, you need to increase the density of the water by dissolving salt into the water.
Limiting Factor: accurate determination of volume of golf ball
Solubility Curve of salt in water. Water has a limit to how much salt can be dissolved.
Saturation – point at which the solution is full and cannot hold anymore solute.
Packing of NaCl Ions
Electron MicroscopePhotograph of NaCl
Dissolving of Salt in Water
NaCl(s) + H2O Na+(aq) + Cl-(aq)
Cl-
ions
Na+
ions Water molecules
Dissolving of Salt in Water
NaCl(s) + H2O Na+(aq) + Cl-(aq)
Cl-
ions
Na+
ions Water molecules
Dissolving of Salt in Water
NaCl(s) + H2O Na+(aq) + Cl-(aq)
Cl-
ions
Na+
ions Water molecules
Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
Dissolving of NaCl
Timberlake, Chemistry 7th Edition, page 287
HH
O
Na+
+
-- + -+
+
-
Cl-
+ -
+
hydrated ions
100 mL
Interstitial Spaces and Particle Size
Interstitial spaces(holes in water where substances dissolve)
Parking at school if you arrive at 7:00 AM = _____
Parking at school if you arrive at 7:45 AM = _____
More available spaces if you arrive early. Salt dissolves quicker when youbegin because there are more available spaces to 'park'.
Analogy: Compact car is easier to park than SUV.
STIR
Easy
Hard
Theory: Crush salt to make particles smaller (increase surface area)…it will dissolve more rapidly.
100 mL of water = 100 g
Add 3.0 mL water,stir…float
You determine the density of golf ball to be 1.18 g/mL
density of water= 1.00 g/mL
Add 19 g salt to 100 g water = 119 g salt + water
Volume remains100 mL (saltwater)
Density = Massvolume
119 g100 mLor
Density (saltwater) = 1.19 g/mL
If golf ball doesn’t float, add 2 mL additions of salt until it floats.
Add 3.0 mL water,stir…floatAdd 3.0 mL water,stir…sink
mL 100salt gx
mL 6 mL 100
g 119
Goals and Objectives: a. Given materials and problem, formulate and test a hypothesis to determine if a golf ball can float in salt water. b. Collect accurate data and compare own data to other class data. Evaluate own results.
Investigation Procedure: a. Design an experiment to accurately determine how dense salt water must be in order for a golf ball to float. Use metric units. Be sure to control as many variables as possible. b. Write down the procedure that you and your partner(s) are going to use prior to lab day. Record any researched facts that may be useful in knowing before conducting your experiment. c. Carefully run your experiment, make observations and record your measurements in a data table. Use grams and milliliters in your measurements. Include a calculation column in your data table. d. Critique your own procedure, discuss and compare your process with another group, then modify your own steps as needed. e. Repeat your experiment to check for accuracy, if time allows.
Discussion Questions for Understanding:
a. How did you determine the density of your golf ball?b. Why does a golf ball normally sink to the bottom of a pond at the golf course?c. What variables were difficult or impossible for you to control during this
experiment? How much salt can be dissolved in 100 mL of water? (saturated) effect of temperature on solubility Surface area of salt may affect rate of dissolving (may need to crush salt finely)d. What variables may have changed as time went on that could have affected
the outcome of your results?e. Did you improve the accuracy of your results after conferring with another
group?f. Describe your sources of error.
(Human error and faulty equipment are unacceptable answers)
Materials: electronic balance 100 mL & 500 mL graduated cylinder mortar / pestle glass stirring rod golf ball salt (Kosher, iodized table salt, table salt) 250 mL beaker
Extension: a. Research the manufacturing of golf balls to determine why they sink in pond water. b. Research to determine which body of salt water in the world would float a golf ball the highest.Lab Report : (10 - 12 point font two page maximum length) Background / problem Hypothesis (if...then) Procedure (protocol) Data (table, graph) Analysis Conclusions / Future directions (limitations) Sample calculations - Appendix
Do not use references to yourself or others in your writing of a lab report (except for citing past research).
ORPoster (25 words or less) A picture is worth 1000 words!
Solid, Liquid, Gas
(a) Particles in solid (b) Particles in liquid (c) Particles in gas
Solid
H2O(s) Ice
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31
Ice
H2O(s) Ice
Photograph of ice model Photograph of snowflakes
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
Liquid
H2O(l) Water
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31
In a liquid• molecules are in constant motion
• there are appreciable intermolecular forces
• molecules are close together
• Liquids are almost incompressible
• Liquids do not fill the container
Gas
H2O(g) Steam
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31
Liquids
The two key properties we need to describe areEVAPORATION and its opposite CONDENSATION
add energy and break intermolecular bonds
EVAPORATION
release energy and form intermolecular bonds
CONDENSATION
States of Matter
Gas, Liquid, and Solid
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 441
Gas Liquid Solid
States of Matter
Solid Liquid Gas
Holds Shape
Fixed Volume
Shape of Container
Free Surface
Fixed Volume
Shape of Container
Volume of Container
heat heat
Some Properties of Solids, Liquids, and Gases
Property Solid Liquid Gas
Shape Has definite shape Takes the shape of Takes the shape the container of its container
Volume Has a definite volume Has a definite volume Fills the volume of the container
Arrangement of Fixed, very close Random, close Random, far apartParticles
Interactions between Very strong Strong Essentially noneparticles
• To evaporate, molecules must have sufficient energy to break IM forces.
• Molecules at the surface break away and become gas.
• Only those with enough KE escape.• Breaking IM forces requires energy. The
process of evaporation is endothermic.• Evaporation is a cooling process.• It requires heat.
Evaporation
Change from gas to liquid
Achieves a dynamic equilibrium with vaporization in a closed system.
What is a closed system?
A closed system means matter can’t go in or out. (put a cork in it)
What the heck is a “dynamic equilibrium?”
Condensation
When first sealed, the molecules gradually escape the surface of the liquid.
As the molecules build up above the liquid - some condense back to a liquid.
The rate at which the molecules evaporate and condense are equal.
Dynamic Equilibrium
As time goes by the rate of vaporization remains constant but the rate of condensation increases because there are more molecules to condense.
Equilibrium is reached when:
Rate of Vaporization = Rate of Condensation
Molecules are constantly changing phase “dynamic”
The total amount of liquid and vapor remains constant “equilibrium”
Dynamic Equilibrium
• Vaporization is an endothermic process - it requires heat.
• Energy is required to overcome intermolecular forces
• Responsible for cool earth• Why we sweat
Vaporization
Energy Changes Accompanying Phase Changes
Solid
Liquid
Gas
Melting Freezing
Deposition
CondensationVaporization
Sublimation
Ene
rgy
of s
yste
m
Brown, LeMay, Bursten, Chemistry 2000, page 405
solid
liquid
gas
Heat added
Tem
pera
ture
(oC
)
A
B
C
DE
Heating Curve for Water
0
100
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487
solid
liquid
gas
vaporization
condensation
melting
freezing
Heat added
Tem
pera
ture
(oC
)
A
B
C
DE
Heating Curve for Water
0
100
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487
Latent Heat
• Take 1 kg of water from –10 oC up to 150 oC we can plot temperature rise against absorbed heat
water
steam(water vapor)
-10 C
0 C
100 C
ice
Lf = 80 cal/g Lv = 540 cal/g
Lf is the latent heat of fusionLv is the latent heat of vaporization
Q heat absorbed
MATTER
Can it be physically separated?
Homogeneous Mixture
(solution)
Heterogeneous Mixture Compound Element
MIXTURE PURE SUBSTANCE
yes no
Can it be chemically decomposed?
noyesIs the composition uniform?
noyes
Colloids Suspensions
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Elements
only one kindof atom; atomsare bonded itthe element
is diatomic orpolyatomic
Compounds
two ormore kindsof atomsthat arebonded
substancewith
definitemakeup
andproperties
Mixtures
two or moresubstances
that arephysically
mixed
two ormore
kinds ofand
Both elements and compounds have a definite makeup and definite properties.
Packard, Jacobs, Marshall, Chemistry Pearson AGS Globe, page (Figure 2.4.1)
Matter Flowchart
Examples:
– graphite
– pepper
– sugar (sucrose)
– paint
– soda
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
element
hetero. mixture
compound
solution homo. mixture
hetero. mixture
Pure Substances
Element– composed of identical atoms– EX: copper wire, aluminum foil
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Pure Substances
Compound– composed of 2 or more elements
in a fixed ratio
– properties differ from those of individual elements
– EX: table salt (NaCl)
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Pure Substances
Law of Definite Composition– A given compound always contains the same,
fixed ratio of elements.
Law of Multiple Proportions– Elements can combine in different ratios to
form different compounds.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Pure Substances
For example…
Two different compounds, each has a definite composition.
Carbon, C Oxygen, O Carbon monoxide, CO
Carbon, C Oxygen, O Oxygen, O Carbon dioxide, CO2
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Mixtures
Variable combination of two or more pure substances.
Heterogeneous Homogeneous
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Mixtures
Solution– homogeneous– very small particles– no Tyndall effect Tyndall Effect
– particles don’t settle– EX: rubbing alcohol
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Mixtures
Colloid– heterogeneous– medium-sized particles– Tyndall effect– particles don’t settle– EX: milk
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Mixtures
Suspension– heterogeneous– large particles– Tyndall effect– particles settle– EX: fresh-squeezed
lemonade
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Mixtures
Examples:
– mayonnaise
– muddy water
– fog
– saltwater
– Italian salad dressing
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
colloid
suspension
colloid
solution
suspension
Classification of Matter
Materials
HomogeneousHeterogeneous
Heterogeneousmixture
Homogeneousmixture
Substance
Element Compound Solution Mixture
Speci
fic /
Gen
eral
Order / Disorder
Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 43
Classification of Matter
MATTER(gas. Liquid,
solid, plasma)
PURESUBSTANCES MIXTURES
HETEROGENEOUSMIXTURE
HOMOGENEOUSMIXTURESELEMENTSCOMPOUNDS
Separated by
physical means into
Separated by
chemical means into
Kotz & Treichel, Chemistry & Chemical Reactivity, 3rd Edition , 1996, page 31
Classification of Matter
uniformproperties?
fixedcomposition?
chemicallydecomposable?
no
no
no
yes
hetero-geneousmixture
solution
element
compound
http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld003.htm
Elements, Compounds, and Mixtures
(a)an element(hydrogen)
(b)a compound(water)
(c)a mixture(hydrogen and oxygen)
(d)a mixture(hydrogenand oxygen)
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68
hydrogenatoms hydrogen
atoms
oxygen atoms
Elements, Compounds, and Mixtures
(a)an element(hydrogen)
(b)a compound(water)
(c)a mixture(hydrogen and oxygen)
(d)a mixture(hydrogenand oxygen)
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68
hydrogenatoms hydrogen
atoms
oxygen atoms
Mixture vs. Compound
Mixture
FixedComposition
Bonds between
components
Can ONLY beseparated by
chemical means
VariableComposition
No bondsbetween
components
Can beseparated by
physical means
Alike Different
Contain two or more
elements
Can beseparated
intoelements
Involvesubstances
Compound
Different
Topic Topic
Compounds vs. Mixtures
• Compounds have properties that are uniquely different from the elements from which they are made. – A formula can always be written for a compound– e.g. NaCl Na + Cl2
• Mixtures retain their individual properties.– e.g. Salt water is salty and wet
Diatomic Elements, 1 and 7H2
N2 O2 F2
Cl2
Br2
F2
Products made from Sulfur
Magazines and printing papersWriting and fine papersWrapping and bag papersSanitary and tissue papersAbsorbent papers
RayonCellophaneCarbon TetrachlorideRuber processing chemicals
Containers and boxesNewsprintPulp for rayon and film
PULP 3%
OTHER 3%
NONACID 12%
InsecticidesFungicidesRubber vulcanizingSoil sulfur
Specialty steels Magnessium Leather processing PhotographyDyestuffs
Bleaching Soybean extraction
Aluminum reductionPaper sizingWater treatmentPharmaceuticalsInsecticidesAntifreeze
Superphosphates Ammonium phosphate Ammonium sulfate Mixed fertilizers
AutosAppliancesTin and other containersGalvanized products
Explosives Nonferrous metals Synthetic rubber Storage batteries Textile finishing
Tire cords Viscose textiles Acetate textiles Blended fabrics Cellophane Photographic film
Paints and enamels Linoleum and coated fabrics Paper Printing inks
Aviation Gasoline
Lubricants
Other Refinery products
SULFURICACID 88%
CARBONDISULFIDE 3%
GROUND &DEFINED 3%
IRON & STEEL 1%
PETROLEUM 2%
CHEMICAL 17%
OTHER INDUSTRIES 6%
RAYON & FILM 3%
TITANIUM AND O
THER
PIGM
ENTS 5%
Synthetic detergents Feed additives Anti-knock gasoline Synthetic resins Protective coating Dyestuffs Oil well acidizingPetroleum catalysts
• Rhombic sulfur– “Brimstone” (when
molten)– Polyatomic (S8)– Forms SO2
Amorphous sulfur – (without shape)
Sulfur
The sudden cooling of m-sulfur produces amorphous sulfur.
Amorphous(Glass)Crystalline
The Haber Process
MatterMatter
SubstanceDefinite composition
(homogeneous)
SubstanceDefinite composition
(homogeneous)
Element(Examples: iron, sulfur,
carbon, hydrogen,oxygen, silver)
Element(Examples: iron, sulfur,
carbon, hydrogen,oxygen, silver)
Mixture ofSubstances
Variable composition
Mixture ofSubstances
Variable composition
Compound(Examples: water.
iron (II) sulfide, methane,Aluminum silicate)
Compound(Examples: water.
iron (II) sulfide, methane,Aluminum silicate)
Homogeneous mixtureUniform throughout,also called a solution
(Examples: air, tap water,gold alloy)
Homogeneous mixtureUniform throughout,also called a solution
(Examples: air, tap water,gold alloy)
Heterogeneous mixtureNonuniform
distinct phases(Examples: soup, concrete, granite)
Heterogeneous mixtureNonuniform
distinct phases(Examples: soup, concrete, granite)
Chemicallyseparable
Physicallyseparable
The Organization of Matter
MATTER
PURESUBSTANCES
HETEROGENEOUSMIXTURE
HOMOGENEOUSMIXTURES
ELEMENTS COMPOUNDS
Physical methods
Chemical methods
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 41
Top Ten Elements in the Universe
Top Ten Elements in the Universe
Percent
Element (by atoms) 1. Hydrogen 73.92. Helium 24.03. Oxygen 1.14. Carbon
0.465. Neon 0.136. Iron 0.117. Nitrogen
0.0978. Silicon 0.0659. Magnesium 0.05810.Sulfur 0.044
A typical spiral galaxy(Milky Way is a spiral galaxy)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 26
The Composition of Air
AirAir
NitrogenNitrogen
OxygenOxygenHeliumHelium
Watervapor
Watervapor
NeonNeon
Carbondioxide
Carbondioxide ArgonArgon
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 34
Chart Examining Some Components of Air
Nitrogen consists of molecules consisting of two atoms of nitrogen:
Oxygen consists of molecules consisting of two atoms of oxygen:
Water consists of molecules consisting of twohydrogen atoms and one oxygen atom:
Argon consists of individual argon atoms:
Carbon dioxide consists of molecules consistingof two oxygen atoms and one carbon atom:
Neon consists of individual neon atoms:
Helium consists of individual helium atoms:
N2
O2
H2O
Ar
CO2
Ne
HeZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 35
Reviewing ConceptsClassifying Matter
• Why does every sample of a given substance have the same properties?
• Explain why the composition of an element is fixed.
• Describe the composition of a compound.• Why can the properties of a mixture vary?• On what basis can mixtures be classified as
solutions, suspensions, or colloids?
Unit Cells
The kind of symmetry found throughout a crystalline substance is determined by the type of unit cell which generates the lattice structure.
Simple cubic Body-centeredcubic
Face-centeredcubic
Monoclinic HexagonalTetragonal
Simple cubic Body-centered cubic Face-centered cubic
Phosphorous (P4)
TWO ALLOTROPIC FORMS
White phosphorousspontaneously ignites
Red phosphorousused for matches
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 457
Sodium Chloride Crystal
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 455
= Cl-
= Na+
Packing of NaCl Ions
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 456
= Na1+= Cl1-
Packing of NaCl Ions
Electron MicroscopePhotograph of NaCl
Molecular Structure of Ice
Hydrogen bonding
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 455
Dry Ice – Carbon Dioxide
Allotropes of Carbon
Graphite BuckminsterfullereneDiamond
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 27
Allotropes of Carbon
Graphite
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
Graphite
Allotropes of Carbon
Diamond
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 455
Diamond
Diamonds in Garage
• Made gem quality diamonds by burning wood
• Scholarship
Molecular structure of diamond
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 476
Molecular structure
of Diamond
Allotropes of Carbon
C60 & C70
“Buckyballs”“Buckytubes”
Buckminsterfullerene
Credit: Baughman et al., Science 297, 787 (2002)
Trojan Horse
Can use ‘camouflage’ to hide things. Be careful what’s in the Trojan!
Buckyballs can hide medicine to treat the human body.
Gold
24 karat gold 18 karat gold 14 karat gold
Gold
Copper
Silver
18/24 atoms Au24/24 atoms Au 14/24 atoms Au
Solid Brass
An alloy is a mixture of metals.
• Brass = Copper + Zinc• Solid brass
• homogeneous mixture• a substitutional alloy
Copper
Zinc
Brass Plated
• Brass = Copper + Zinc• Brass plated
• heterogeneous mixture• Only brass on outside
Copper
Zinc
Steel Alloys
• Stainless steel• Tungsten hardened steel• Vanadium steel• We can engineer properties
– Add carbon to increase strength– Too much carbon too brittle and snaps– Too little carbon too ductile and iron bends
Tens
ile s
tren
gth
Force is added
Galvanized Nails and Screws
• Zinc coating prevents rust– Use deck screws for any outdoor project
• Iron will rust if untreated – Weaken and break
Nitinol Wire
• Alloy of nickel and titanium• Remembers shape when heated
Applications:
surgery, shirts that do not need to be ironed.
Properties of Matter
• Electrical Conductivity• Heat Conductivity• Density• Melting Point• Boiling Point• Malleability• Ductility
Methods of Separating Mixtures
• Magnet• Filter• Decant• Evaporation• Centrifuge• Chromatography• Distillation
Filtration separates
a liquid from a solid
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40
Mixture ofsolid andliquid Stirring
rod
Filtrate (liquidcomponentof the mixture)
Filter papertraps solid
Funnel
Chromatography
• Tie-dye t-shirt
• Black pen ink
• DNA testing– Tomb of Unknown Soldiers– Crime scene – Paternity testing
Paper Chromatography
Paper Chromatographyof Water-Soluble Dyes
orange red yellow
Initial spots of dyes
Direction of Water(mobile phase)
movement
Filter paper(stationary phase)
Orange mixture ofredand
yellow
Suggested red dyeis not
homogeneous
Separation by Chromatography
samplemixture
a chromatographic column
stationary phaseselectively absorbs
components
mobile phasesweeps sampledown column
detector
http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm
Separation by Chromatography
samplemixture
a chromatographic column
stationary phaseselectively absorbs
components
mobile phasesweeps sampledown column
detector
http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm
Ion chromatogram of orange juice
time (minutes)
de
tec
tor
res
po
ns
e
0 5 10 15 20 25
Na+
K+
Mg2+ Fe3+
Ca2+
Setup to heat a solution
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 42
Ring stand
Beaker
Wire gauze
Ring
Bunsen burner
long spout helpsvapors to condense
mixture for distillation placed in here
Furnace
Glass retortGlass Retort
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 13
A Distillation Apparatus
liquid with a soliddissolved in it
thermometer
condenser
tube
distillingflask
pure liquid
receiving flaskhose connected to
cold water faucetDorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 282
The solution is boiled and steam is driven off.
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 39
Salt remains after all water is boiled off.
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 39
No chemical change occurs when salt water is distilled.
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40
Saltwater solution(homogeneous mixture)
Distillation(physical method)
Salt
Pure water
Separation of a sand-saltwater mixture.
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40
Separation of Sand from Salt1. Gently break up your salt-crusted sand with a plastic spoon.
Follow this flowchart to make a complete separation.
Salt-crusted
sand.
Dry
sand.
Wetsand.
Weigh themixture.
Decant clearliquid.
Evaporateto
dryness.
Pour intoheat-resistant
container.
Fill with water.
Stir and letsettle 1 minute.
Weighsand.
Calculateweight of
salt.
Repeat3 times?
Yes
No
2. How does this flowchart insure a completeseparation?
Four-stroke Internal Combustion Engine
Different Types of Fuel Combustion
2 C8H18 + 25 O2 16 CO2 + 18 H2O
__CH3OH +__O2 __CO2 +__H2O
Methanol (in racing fuel)
Gasoline (octane)
Combustion Chamber
- The combustion chamber is the area where compression and combustion take place.
- Gasoline and air must be mixed in the correct ratio.
• Methanol can run at much higher compression ratios, meaning that you can get more power from the engine on each piston stroke.
• Methanol provides significant cooling when it evaporates in the cylinder, helping to keep the high-revving, high-compression engine from overheating.
• Methanol, unlike gasoline, can be extinguished with water if there is a fire. This is an important safety feature.
• The ignition temperature for methanol (the temperature at which it starts burning) is much higher than that for gasoline, so the risk of an accidental fire is lower.
The Advantages of Methanol - Burning
Engines
• At 900 hp, it has about two to three times the horsepower of a "high-performance" automotive engine. For example, Corvettes or Vipers might have 350- to 400-horsepower engines.
• At 15,000 rpm, it runs at about twice the rpm of a normal automotive engine. Compared to a normal engine, an methanol engine has larger pistons and the pistons travel a shorter distance up and down on each stroke.
• The motor is lighter. This lowers their inertia and is another factor in the high rpm.
A Race Car - Basic Information
Centrifugation
• Spin sample very rapidly: denser materials go to bottom (outside)
• Separate blood into serum and plasma– Serum (clear)– Plasma (contains red blood
cells ‘RBCs’)• Check for anemia (lack of iron)
Blood
RBC’s
Serum
A B C
AFTER
Before
Water Molecules
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 8
The decomposition of two water molecules.
2 H2O O2 + 2 H2
Electriccurrent
Watermolecules
Diatomic Diatomicoxygen molecule hydrogen molecules+
Electrolysis
*Must add acid catalyst to conduct electricity
*H1+
water oxygen hydrogen
“electro” = electricity “lysis” = to split
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 32
Water
Hydrogengas forms
Oxygengas forms
ElectrodeSource ofdirect current
H2O(l) O2 (g) + 2 H2 (g)
Electrolysis of Water
Half reaction at the cathode (reduction): 4 H2O + 4 e - 2 H2 + 4 OH 1-
Half reaction at the anode (oxidation): 2 H2O O2 + 4 H 1+ + 4 e -
hydrogengas
cathode
oxygengas
anode
D.C. powersource
water
Reviewing ConceptsPhysical Properties
• List seven examples of physical properties.
• Describe three uses of physical properties.• Name two processes that are used to
separate mixtures.• When you describe a liquid as thick, are
you saying that it has a high or low viscosity?
Reviewing ConceptsPhysical Properties
• Explain why sharpening a pencil is an example of a physical change.
• What allows a mixture to be separated by distillation?
Reviewing ConceptsChemical Properties
• Under what conditions can chemical properties be observed?
• List three common types of evidence for a chemical change.
• How do chemical changes differ from physical changes?
Reviewing ConceptsChemical Properties
• Explain why the rusting of an iron bar decreases the strength of the bar.
• A pat of butter melts and then burns in a hot frying pan. Which of these changes is physical and which is chemical?
2 H22 H2 O2
O2 2 H2O2 H2O++ ++ EE
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
The Zeppelin LZ 129 Hindenburg catching fire on May 6, 1937 at Lakehurst Naval Air Station in New Jersey.
S.S. Hindenburg
35 people died when the Hindenburg exploded.
May 1937 at Lakehurst, New Jersey
• German zeppelin luxury liner
• Exploded on maiden voyage
• Filled with hydrogen gas
Hydrogen is the most effective buoyant gas,but is it highly flammable. The disastrous fire in the Hindenburg, a hydrogen-filled dirigible, in 1937 led to the replacement of hydrogen by nonflammable helium.
Erosion Takes a Powder
TreatedUntreated
Top so
il runoff
Sodium Polyacrylate
• Absorbent Material– Absorbs 700x volume of water
• Magicians– Pour water in hat and it “disappears”
• Diapers• Farmers
– Anti-erosion powder• Add to Soils
– hold moisture between watering
Specific Heats of Some Substances
Specific Heat
Substance (cal/ g oC) (J/g oC)
Water 1.00 4.18Alcohol 0.58 2.4Wood 0.42 1.8Aluminum 0.22 0.90Sand 0.19 0.79Iron 0.11 0.46Copper 0.093 0.39Silver 0.057 0.24Gold 0.031 0.13
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
(a) Radiant energy (b) Thermal energy
(c) Chemical energy (d) Nuclear energy (e) Electrical energy
The energy something possesses due to its motion, depending on mass and velocity.
Potential energy
Energy in Energy out
kinetic energy kinetic energy
School Bus or Bullet?
Which has more kinetic energy; a slow moving school bus or a fast moving bullet?
Recall: KE = ½ m v 2
KE = ½ m v 2 KE = ½ m v
2
BUS BULLET
KE(bus) = ½ (10,000 lbs) (0.5 mph)2 KE(bullet) = ½ (0.002 lbs) (240 mph)2
Either may have more KE, it depends on the mass of the bus and the velocity of the bullet.
Which is a more important factor: mass or velocity? Why? (Velocity)2
Kinetic Energy and Reaction Rate
Kinetic energy
Fra
ctio
ns o
f pa
rtic
les
lower temperature
higher temperature
minimum energyfor reaction
Kinetic Energy and Reaction Rate
Kinetic energy
Fra
ctio
ns o
f pa
rtic
les
lower temperature
higher temperature
minimum energyfor reaction
Hot vs. Cold Tea
Kinetic energy
Many molecules have anintermediate kinetic energy
Few molecules have avery high kinetic energy
Low temperature(iced tea)
High temperature(hot tea)
Perc
ent o
f mol
ecul
es
Decomposition of Nitrogen Triiodide
Decomposition of Nitrogen Triiodide
2 NI3(s) N2(g) + 3 I2(g)
NI3 I2
N2
Exothermic ReactionReactants Products + Energy 10 energy = 8 energy + 2 energy
Reactants
Products
-DH
Ene
rgy
Energy of reactants
Energy of products
Reaction Progress
Endothermic Reaction
Energy + Reactants Products
+DH Endothermic
Reaction progress
Ene
rgy
Reactants
ProductsActivation Energy
Effect of Catalyst on Reaction Rate
reactants
products
Ene
rgy
activation energy for catalyzed reaction
Reaction Progress
No catalyst
Catalyst lowers the activation energy for the reaction.What is a catalyst? What does it do during a chemical reaction?
An Energy Diagram
activatedcomplex
activationenergyEa
reactants
products
course of reaction
ener
gy
Animation by Raymond ChangAll rights reserved
Energy Sources in the United States
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 307
Wood Coal Petroleum / natural gas Hydro and nuclear
1850 1900 1940 1980 1990
100
80
60
40
20
0
Per
cent
9
91
21
71
5 310
50
40
20
70
10
26
58
16
Energy Sources in the United States
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 307
Wood Coal Petroleum / natural gas Hydro and nuclear
1850
100
80
60
40
20
0
Per
cent
9
91
1900
21
71
5 3
1940
10
50
40
1980
20
70
10
1990
26
58
16
Energy Sources in the United States
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 307
Wood Coal Petroleum / natural gas Hydro and nuclear
1850
100
80
60
40
20
0
Per
cent
9
91
1900
21
71
5 3
1940
10
50
40
1980
20
70
10
1990
26
58
16
2005
50
21 26
Energy Conversion
Timberlake, Chemistry 7th Edition, page 202
fanelectrical energy tomechanical energy
light bulbelectrical energy to
light energy tothermal and radiant energy
coffee makerelectrical energy to
thermal energy
pencil sharpenerelectrical energy tomechanical energy
Conservation of Energy in a Chemical Reaction
Surroundings
System
Surroundings
SystemEn
erg
y
Beforereaction
Afterreaction
In this example, the energy of the reactants and products increases, while the energy of the surroundings decreases.
In every case, however, the total energy does not change.
Myers, Oldham, Tocci, Chemistry, 2004, page 41
Endothermic Reaction
Reactant + Energy Product
Conservation of Energy in a Chemical Reaction
Surroundings
System
Surroundings
System
En
erg
y
Beforereaction
Afterreaction
In this example, the energy of the reactants and products decreases, while the energy of the surroundings increases.
In every case, however, the total energy does not change.
Myers, Oldham, Tocci, Chemistry, 2004, page 41
Exothermic Reaction
Reactant Product + Energy
Direction of Heat Flow
Surroundings
ENDOthermicqsys > 0
EXOthermicqsys < 0
System
Kotz, Purcell, Chemistry & Chemical Reactivity 1991, page 207
System
H2O(s) + heat H2O(l)
melting
H2O(l) H2O(s) + heat
freezing
Caloric Values
Food joules/grams calories/gram Calories/gram
Protein 17 000 4000 4
Fat 38 000 9000 9
Carbohydrates 17 000 4000 4
Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 51
1000 calories = 1 Calorie
"science" "food"
1calories = 4.184 joules
Units of energy
Most common units of energy
1. S unit of energy is the joule (J), defined as 1 (kilogram•meter2)/second2, energy is also
expressed in kilojoules (1 kJ = 103J).
2. Non-S unit of energy is the calorie where 1 calorie (cal) is the amount of energy needed
to raise the temperature of 1 g of water by 1°C.
One cal = 4.184 J or 1J = 0.2390 cal.
Units of energy are the same, regardless of the form of energy
Typical apparatus used in this activity include a boiler (such as large glass beaker), a heat source (Bunsen burner or hot plate), a stand or tripod for the boiler, a calorimeter, thermometers, samples (typically samples of copper, aluminum, zinc, tin, or lead), tongs (or forceps or string) to handle samples, and a balance.
Experimental Determination of Specific Heat of a Metal
A Coffee Cup Calorimeter
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 302
Thermometer
Styrofoamcover
Styrofoamcups
Stirrer
Thermometer
Glass stirrer
Cork stopper
Two Styrofoam ®cups nestedtogether containingreactants in solution
A Bomb Calorimeter
Heating Curves
Melting - PE
Solid - KE
Liquid - KE
Boiling - PE
Gas - KE
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Heating CurvesTe
mp
erat
ure
(oC
)
40
20
0
-20
-40
-60
-80
-100
120
100
80
60
140
Time
Melting - PE
Solid - KE
Liquid - KE
Boiling - PE
Gas - KE
Heating Curves
• Temperature Change– change in KE (molecular motion) – depends on heat capacity
• Heat Capacity– energy required to raise the temp of 1 gram of a
substance by 1°C– “Volcano” clip -– water has a very high heat capacity
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Heating Curves
• Phase Change– change in PE (molecular arrangement)– temp remains constant
• Heat of Fusion (Hfus)– energy required to melt 1 gram of a substance at its
m.p.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Heating Curves
• Heat of Vaporization (Hvap)– energy required to boil 1 gram of a substance at its
b.p.– usually larger than Hfus…why?
• EX: sweating, steam burns, the drinking bird
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Phase Diagrams
• Show the phases of a substance at different temps and pressures.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Calculating Energy Changes - Heating Curve for Water
Tem
per
atu
re (
oC
)
40
20
0
-20
-40
-60
-80
-100
120
100
80
60
140
Time
DH = mol x DHfus
DH = mol x DHvap
Heat = mass x Dt x Cp, liquid
Heat = mass x Dt x Cp, gas
Heat = mass x Dt x Cp, solid
Equal Masses of Hot and Cold Water
Thin metal wall
Insulated box Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Water Molecules in Hot and Cold Water
Hot water Cold Water90 oC 10 oC
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Water Molecules in the same temperature water
Water(50 oC)
Water(50 oC)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 291
Heat Transfer
Al Al
m = 20 gT = 40oC
SYSTEM
Surroundings
m = 20 gT = 20oC
20 g (40oC) 20 g (20oC) 30oC
Block “A” Block “B”Final
Temperature
Assume NO heat energy is “lost” to the surroundings from the system.
C30
g) 20 g (20C20g 20C40g 20 o
oo
What will be the final temperature of the system ?
a) 60oC b) 30oC c) 20oC d) ?
Heat Transfer
AlAl
m = 20 gT = 40oC
SYSTEM
Surroundings
m = 10 gT = 20oC
20 g (40oC) 20 g (20oC) 30.0oC
Block “A” Block “B”Final
Temperature
Assume NO heat energy is “lost” to the surroundings from the system.
20 g (40oC) 10 g (20oC) 33.3oC
C3.33
g) 10 g (20C20g 10C40g 20 o
oo
What will be the final temperature of the system ?
a) 60oC b) 30oC c) 20oC d) ?
?
Heat Transfer
AlAl
m = 20 gT = 20oC
SYSTEM
Surroundings
m = 10 gT = 40oC
20 g (40oC) 20 g (20oC) 30.0oC
Block “A” Block “B”Final
Temperature
Assume NO heat energy is “lost” to the surroundings from the system.
20 g (40oC) 10 g (20oC) 33.3oC
C7.26
g) 10 g (20C40g 10C20g 20 o
oo
20 g (20oC) 10 g (40oC) 26.7oC
Heat Transfer
m = 75 gT = 25oC
SYSTEM
Surroundings
m = 30 gT = 100oC
20 g (40oC) 20 g (20oC) 30.0oC
Block “A” Block “B”Final
Temperature
20 g (40oC) 10 g (20oC) 33.3oC
C46
g) 30 g (75C100g 30C25g 75 o
oo
20 g (20oC) 10 g (40oC) 26.7oC
AgH2O
Real Final Temperature = 26.6oC
Why?
We’ve been assuming ALL materialstransfer heat equally well.
Specific Heat
• Water and silver do not transfer heat equally well. Water has a specific heat Cp = 4.184 J/goC Silver has a specific heat Cp = 0.235 J/goC
• What does that mean? It requires 4.184 Joules of energy to heat 1 gram of water 1oC and only 0.235 Joules of energy to heat 1 gram of silver 1oC.
• Law of Conservation of Energy… In our situation (silver is “hot” and water is “cold”)… this means water heats up slowly and requires a lot of energy
whereas silver will cool off quickly and not release much energy.
• Lets look at the math!
“loses” heat
Calorimetry
C26.6 x
320.8x 8550
7845 313.8x x 05.7 705
algebra. the solve and units Drop
C25 -x g 75CgJ 184.4 C100 -x g 30CgJ 235.0
equation. into values Substitute
TTmC TTmC
TmC TmC
q q
o
oooo
ifpinitialfinalp
pp
OHAg 2
m = 75 gT = 25oC
SYSTEM
Surroundings
m = 30 gT = 100oC
AgH2O
Tfinal = 26.6oC
Calorimetry
C26.6 x
8550 320.8x
7845 313.8x x 05.7 705
algebra. the solve and units Drop
C25 -x g 75CgJ 184.4 C100 -x g 30CgJ 235.0
equation. into values Substitute
TTmC TTmC
TmC TmC
q q
o
oooo
ifpinitialfinalp
pp
OHAg 2
m = 75 gT = 25oC
SYSTEM
Surroundings
m = 30 gT = 100oC
AgH2O
1 Calorie = 1000 calories
“food” = “science”
Candy bar300 Calories = 300,000 calories
English
Metric = _______Joules
1 calorie - amount of heat needed to raise 1 gram of water 1oC
1 calorie = 4.184 Joules
Cp(ice) = 2.077 J/g oC
It takes 2.077 Joules to raise 1 gram ice 1oC.
X Joules to raise 10 gram ice 1oC.
(10 g)(2.077 J/g oC) = 20.77 Joules
X Joules to raise 10 gram ice 10oC.
(10oC)(10 g)(2.077 J/g oC) = 207.7 Joules
Heat = (specific heat) (mass) (change in temperature)
q = Cp . m . DTTe
mpe
ratu
re (
o C)
40200
-20-40-60-80
-100
120100
8060
140
Time
DH = mol x DHfus
DH = mol x DHvap
Heat = mass x Dt x Cp, liquid
Heat = mass x Dt x Cp, gas
Heat = mass x Dt x Cp, solid
Heat = (specific heat) (mass) (change in temperature)
q = Cp . m . DT
T m C q p(ice)
initialfinalp(ice) TT m C q
C)30(C20- g 10 C g
J 2.077 q oo
o
Given Ti = -30oC
Tf = -20oC
q = 207.7 Joules
Tem
pera
ture
(o C
)
40200
-20-40-60-80
-100
120100
8060
140
Time
DH = mol x DHfus
DH = mol x DHvap
Heat = mass x Dt x Cp, liquid
Heat = mass x Dt x Cp, gas
Heat = mass x Dt x Cp, solid
240 g of water (initially at 20oC) are mixed with an unknown mass of iron (initially at 500oC). When thermal equilibrium is reached, the system has a temperature of 42oC. Find the mass of the iron.
Calorimetry Problems 2 question #5
FeT = 500oCmass = ? grams
T = 20oC
mass = 240 g LOSE heat = GAIN heat-
- [(Cp,Fe) (mass) (T)] = (Cp,H2O) (mass) (T)
- [(0.4495 J/goC) (X g) (42oC - 500oC)] = (4.184 J/goC) (240 g) (42oC - 20oC)]
Drop Units: - [(0.4495) (X) (-458)] = (4.184) (240 g) (22)
205.9 X = 22091
X = 107.3 g Fe
A 97 g sample of gold at 785oC is dropped into 323 g of water, which has an initial temperature of 15oC. If gold has a specific heat of 0.129 J/goC, what is the final temperature of the mixture? Assume that the gold experiences no change in state of matter.
Calorimetry Problems 2 question #8
AuT = 785oCmass = 97 g
T = 15oC
mass = 323 g
LOSE heat = GAIN heat-
- [(Cp,Au) (mass) (T)] = (Cp,H2O) (mass) (T)
- [(0.129 J/goC) (97 g) (Tf - 785oC)] = (4.184 J/goC) (323 g) (Tf - 15oC)] Drop Units:
- [(12.5) (Tf - 785oC)] = (1.35x 103) (Tf - 15oC)]
-12.5 Tf + 9.82 x 103 = 1.35 x 103 Tf - 2.02 x 104
3 x 104 = 1.36 x 103 Tf
Tf = 22.1oC
If 59 g of water at 13oC are mixed with 87 g of water at 72oC, find the final temperature of the system.
Calorimetry Problems 2 question #9
T = 13oC
mass = 59 g
LOSE heat = GAIN heat-
- [(Cp,H2O) (mass) (T)] = (Cp,H2O) (mass) (T)
- [(4.184 J/goC) (59 g) (Tf - 13oC)] = (4.184 J/goC) (87 g) (Tf - 72oC)] Drop Units:
- [(246.8) (Tf - 13oC)] = (364.0) (Tf - 72oC)]
-246.8 Tf + 3208 = 364 Tf - 26208
29416 = 610.8 Tf
Tf = 48.2oC
T = 72oC
mass = 87 g
A 38 g sample of ice at -11oC is placed into 214 g of water at 56oC. Find the system's final temperature.
Calorimetry Problems 2 question #10
iceT = -11oCmass = 38 g
T = 56oC
mass = 214 g
LOSE heat = GAIN heat-
- [(Cp,H2O) (mass) (T)] = (Cp,H2O) (mass) (T) + (Cf) (mass) + (Cp,H2O) (mass) (T)
- [(4.184 J/goC)(214 g)(Tf - 56oC)] = (2.077 J/goC)(38 g)(11oC) + (333 J/g)(38 g) + (4.184 J/goC)(38 g)(Tf - 0oC)
- [(895) (Tf - 56oC)] = 868 + 12654 + (159) (Tf)]
- 895 Tf + 50141 = 868 + 12654 + 159 Tf
- 895 Tf + 50141 = 13522 + 159 Tf
Tf = 34.7oC
36619 = 1054 Tf
Tem
pera
ture
(o C
)
40200
-20-40-60-80
-100
120100
8060
140
Time
DH = mol x DHfus
DH = mol x DHvap
Heat = mass x Dt x Cp, liquid
Heat = mass x Dt x Cp, gas
Heat = mass x Dt x Cp, solid
A
B
C
D
warm icemelt ice
warm water
water cools
25 g of 116oC steam are bubbled into 0.2384 kg of water at 8oC. Find the final temperature of the system.
Calorimetry Problems 2 question #11
- [(Cp,H2O) (mass) (T)] + (Cv,H2O) (mass) + (Cp,H2O) (mass) (T) = [(Cp,H2O) (mass) (T)]
- [ - 816.8 - 56400 + 104.5Tf - 10450] = 997Tf - 7972
- [qA + qB + qC] = qD
qA = [(Cp,H2O) (mass) (T)]
qA = [(2.042 J/goC) (25 g) (100o - 116oC)]
qA = - 816.8 J
qB = (Cv,H2O) (mass)
qA = (2256 J/g) (25 g)
qA = - 56400 J
qC = [(Cp,H2O) (mass) (T)]
qC = [(4.184 J/goC) (25 g) (Tf - 100oC)]
qA = 104.5Tf - 10450
qD = (4.184 J/goC) (238.4 g) (Tf - 8oC)
qD = - 997Tf - 7972
- [qA + qB + qC] = qD
816.8 + 56400 - 104.5Tf + 10450 = 997Tf - 7972
67667 - 104.5Tf = 997Tf - 7979
75646 = 1102Tf
1102 1102
Tf = 68.6oC
Tem
pera
ture
(o C
)
40200
-20-40-60-80
-100
120100
8060
140
Time
DH = mol x DHfus
DH = mol x DHvap
Heat = mass x Dt x Cp, liquid
Heat = mass x Dt x Cp, gas
Heat = mass x Dt x Cp, solid
A
B
C
D
(1000 g = 1 kg)
238.4 g
A 322 g sample of lead (specific heat = 0.138 J/goC) is placed into 264 g of water at 25oC.If the system's final temperature is 46oC, what was the initial temperature of the lead?
Calorimetry Problems 2 question #12
PbT = ? oCmass = 322 g
Ti = 25oC
mass = 264 g
LOSE heat = GAIN heat-
- [(Cp,Pb) (mass) (T)] = (Cp,H2O) (mass) (T)
- [(0.138 J/goC) (322 g) (46oC - Ti)] = (4.184 J/goC) (264 g) (46oC- 25oC)] Drop Units:
- [(44.44) (46oC - Ti)] = (1104.6) (21oC)]
- 2044 + 44.44 Ti = 23197
44.44 Ti = 25241
Ti = 568oC
Pb
Tf = 46oC
A sample of ice at –12oC is placed into 68 g of water at 85oC. If the final temperature of the system is 24oC, what was the mass of the ice?
Calorimetry Problems 2 question #13
H2OT = -12oCmass = ? g
Ti = 85oC
mass = 68 g
GAIN heat = - LOSE heat
[ qA + qB + qC ] = - [(Cp,H2O) (mass) (T)]
458.2 m = - 17339
m = 37.8 g
iceTf = 24oC
qA = [(Cp,H2O) (mass) (T)]
qC = [(Cp,H2O) (mass) (T)]
qB = (Cf,H2O) (mass)
qA = [(2.077 J/goC) (mass) (12oC)]
qB = (333 J/g) (mass)
qC = [(4.184 J/goC) (mass) (24oC)]
[ qA + qB + qC ] = - [(4.184 J/goC) (68 g) (-61oC)]
24.9 m
333 m
100.3 m
458.2 mqTotal = qA + qB + qC
458.2 458.2
Endothermic Reaction
Energy + Reactants Products
+DH Endothermic
Reaction progress
Ene
rgy
Reactants
ProductsActivation Energy
Catalytic Converter
Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 454
N O
N O
N O
N O
N O
NO
N
O
NO
N O
N
O
N
O
O ON
NO
O
OO
N NNN
One of the reactions that takes place in the catalytic converter is the decomposition of nitrogen (II) oxide (NO) to nitrogen and oxygen gas.
N O
O
Catalytic Converter
C O
N O
CO
OCO
NN
One of the reactions that takes place in the catalytic converter is the decomposition of carbon monoxide (CO) to carbon dioxide and nitrogen (II) oxide (NO) to nitrogen gas.
CO
N
NN
OO
OC
OCO
2 CO(g) + 2 NO(g) N2(g) + 2 CO2(g)catalyst
Enthalpy Diagram
H2O(g)H2O(g)
H2O(l)H2O(l)
H2(g) + ½ O2(g)
- 44 kJExothermic
+44 kJEndothermic
DH = +242 kJEndothermic
-242 kJExothermic
-286 kJEndothermic
DH = -286 kJExothermic
Ene
rgy
H2(g) + 1/2O2(g) H2O(g) + 242 kJ DH = -242 kJKotz, Purcell, Chemistry & Chemical Reactivity 1991, page 211
Hess’s LawCalculate the enthalpy of formation of carbon dioxide from its elements.
C(g) + 2O(g) CO2(g)
Use the following data:2O(g) O2(g) DH = - 250 kJC(s) C(g) DH = +720 kJCO2(g) C(s) + O2(g) DH = +390 kJ
Smith, Smoot, Himes, pg 141
2O(g) O2(g) DH = - 250 kJ
C(g) + 2O(g) CO2(g) DH = -1360 kJ
C(g) C(s) DH = - 720 kJC(s) + O2(g) CO2(g) DH = - 390 kJ
In football, as in Hess's law, only the initial and final conditions matter.A team that gains 10 yards on a pass play but has a five-yard penalty,has the same net gain as the team that gained only 5 yards.
initial positionof ball
final positionof ball
10 yard pass
5 yard penalty
5 yard net gain
Fission vs. Fusion
Fuse small atoms2H2 He
NO Radioactive
waste
Very HighTemperatures~5,000,000 oC
(SUN)
Split large atoms
U-235
Radioactive waste
(long half-life)
NuclearPowerPlants
Alike Different
Create Large Amounts
of EnergyE = mc2
Transmutationof Elements
Occurs
Change Nucleus
of Atoms
Fusion
Different
Topic Topic
Fission
• Use fear and selective facts
to promote an agenda
• Eating animals?• Radiation = Bad
Look who is funding research; it may bias the results.
Shielding Radiation
Nuclear Fission
First stage: 1 fission Second stage: 2 fission Third stage: 4 fission
Nuclear Fission
Nuclear Power Plants
map: Nuclear Energy Institute
Fermi Approximations
FERMI APPROXIMATIONS An educated guess – based on a seriesof calculations of known facts – to arriveat a reasonable answer to a question.
How many piano tuners are there in New York City?
ANSWER:
Enrico Fermi
400 piano tuners
Nuclear Fusion
Sun
+ +
Fourhydrogen
nuclei(protons)
Two betaparticles
(electrons)
Oneheliumnucleus
He e2 H4 4
2
0
1-
1
1 + Energy
Conservation of Mass…mass is converted into energy
Hydrogen (H2) H = 1.008 amuHelium (He) He = 4.004 amu
FUSION
2 H2 1 He + ENERGY
1.008 amux 44.0032 amu = 4.004 amu + 0.028 amu
This relationship was discovered by Albert EinsteinE = mc2
Energy= (mass) (speed of light)2
Time Travel?
…Albert Einstein also discovered the Geometry of Space Near a Black Hole
Einstein’s theory of general relativity maybe interpreted interms of curvature of space in the presence of a gravitationalfield. Here we see how this curvature varies near a black hole.
Time Travel?
…Albert Einstein also discovered the Geometry of Space Near a Black Hole
Einstein’s theory of general relativity maybe interpreted interms of curvature of space in the presence of a gravitationalfield. Here we see how this curvature varies near a black hole.
Time Travel?
…Albert Einstein also discovered the Geometry of Space Near a Black Hole
Einstein’s theory of general relativity maybe interpreted interms of curvature of space in the presence of a gravitationalfield. Here we see how this curvature varies near a black hole.
Tokamak Reactor
• Fusion reactor• 10,000,000 o Celcius• Russian for torroidial
(doughnut shaped) ring
• Magnetic field contains plasma
Cold Fusion?
• Fraud?• Experiments must
be repeatable to
be valid
0 1 2 3 4Number of half-lives
Rad
iois
otop
e re
mai
ning
(%
)
100
50
25
12.5
Half-life of Radiation
Initial amountof radioisotope
t1/2
t1/2
t1/2
After 1 half-life
After 2 half-lives
After 3 half-lives
Triple Point Plot
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 488
solidliquid
gas
melting
freezing
sublimation
deposition
vaporization
condensation
Temperature (oC)
Pre
ssur
e (a
tm)
0.6
2.6
Liquid VaporSolid
Normalmelting point
Normalboilingpoint
101.3
0.61
0.016 1000Temperature (oC)
Pre
ssu
re (
KP
a)
Triple point
Triple Point
Criticalpressure
Critical point
Critical temperature
373.99
22,058
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
Objectives - Matter
• Explain why mass is used as a measure of the quantity of matter.
• Describe the characteristics of elements, compounds, and mixtures.
• Solve density problems by applying an understanding of the concepts of density.
• Distinguish between physical and chemical properties and physical and chemical changes.
• Demonstrate an understanding of the law of conservation of mass by applying it to a chemical reaction.
Objectives - Energy
• Identify various forms of energy.• Describe changes in energy that take place
during a chemical reaction.• Distinguish between heat and temperature.• Solve calorimetry problems.• Describe the interactions that occur between
electrostatic charges.
Law of Conservation of EnergyEafter = Ebefore
2 H2 + O2 2 H2O + energy
+ + WOOF!
Law of Conservation of Energy
ENERGY
CO2 + H2OC2H2 + O2
PEreactants
PEproducts
KEstopper
heat, light, sound
Eafter = Ebefore
2 H2 + O2 2 H2O + energy
+ + WOOF!
Law of Conservation of Energy
ENERGY
C2H2 + O2C2H2 + O2
PEreactants
PEproducts
KEstopper
heat, light, sound
Eafter = Ebefore
2C2H2 + 5O2 4 CO2 + 2H2O + energy
Energy Changes
First experimental image showing internal atomic structures
© 2005 University of Augsburg, Experimental Physics VI, http://www.physik.uni-augs
Heating CurvesHeating CurvesTe
mp
erat
ure
(oC
)
40
20
0
-20
-40
-60
-80
-100
120
100
80
60
140
Time
Melting - PE
Solid - KE
Liquid - KE
Boiling - PE
Gas - KE
Heating CurvesHeating Curves
Temperature Change• change in KE (molecular motion) • depends on heat capacity
Heat Capacity• energy required to raise the temp of 1
gram of a substance by 1°C• “Volcano” clip - water has a very high
heat capacityCourtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Heating CurvesHeating Curves
Phase Change• change in PE (molecular arrangement)• temp remains constant
Heat of Fusion (Hfus)
• energy required to melt 1 gram of a substance at its m.p.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Heating CurvesHeating Curves
Heat of Vaporization (Hvap)• energy required to boil 1 gram of a
substance at its b.p.• usually larger than Hfus…why?
EX: sweating, steam burns, the drinking bird
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Phase DiagramsPhase Diagrams
Show the phases of a substance at different temps and pressures.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Resources - Matter and Energy
Objectives - matter and energy
Objectives - measurement
Objectives - phases of matter
Worksheet - vocabulary
Worksheet II - percentage composition
Worksheet - properties
Worksheet - density problems
Activity - density blocks & Part 2
Lab - golf ball lab
Worksheet - classifying matter
Outline (general)
Activity - chromatography
Outline - causes of change - calorimetry
Worksheet - calorimetry problems 1
Worksheet - calorimetry problems 2
Worksheet - heat energy problems
Worksheet - conversion factors
Worksheet - atoms, mass, and the mole
activity - mole pattern
Article - buried in ice (questions) Lab - beverage density (PowerPoint)
Textbook - questions
Article - buckyball (pics) & (video) questions
Episode 5 - A Matter of State
General Chemistry PP