1. Matter Notes Note :Slide 1-38 (Packet 1 ) , Slide 39-49 (Packet 2)
Chemistry Ch 3

2. The Nature of Matter Gold Mercury
Chemists are interested in the nature of matter and how this is related to its atoms and molecules.

3. Chemistry & Matter
We can explore the MACROSCOPIC world — what we can see —
to understand the PARTICULATE worlds we cannot see.
We write SYMBOLS to describe these worlds.

4. A Chemist’s View of Water
Macroscopic
H2O
(gas, liquid, solid)
Symbolic
Particulate

5. A Chemist’s View Macroscopic 2 H2(g) + O2 (g) --> 2 H2O(g)
Particulate
Symbolic

6. Kinetic Nature of Matter
Matter consists of atoms and molecules in motion.

7. STATES OF MATTER
SOLIDS — have rigid shape, fixed volume. External shape can reflect the atomic and molecular arrangement.
Reasonably well understood.
LIQUIDS — have no fixed shape and may not fill a container completely.
Not well understood.
GASES — expand to fill their container.
Good theoretical understanding.

8. OTHER STATES OF MATTER
PLASMA — an electrically charged gas; Example: the sun or any other star

9. Physical Properties of Matter

10. STATES OF MATTER: SOLIDS
Particles of solids are tightly packed, vibrating about a fixed position.
Solids have a definite shape and a definite volume.
Heat

11. STATES OF MATTER LIQUID
Particles of liquids are tightly packed, but are far enough apart to slide over one another.
Liquids have an indefinite shape and a definite volume.
Heat

12. STATES OF MATTER GAS
Particles of gases are very far apart and move freely.
Gases have an indefinite shape and an indefinite volume.
Heat

13. The phase change from a solid to liquid is called melting.

15. 17. Describe how taking a shower is an example of condensation.

16. 18. The phase change from a liquid back to a solid is called Freezing

17. 19. Dry ice turning directly into a gas is an example of what kind of phase change? (solid gas) sublimation

18. Gas – Solid

19. Phase Change

22. Physical Properties What are some physical properties? color
melting and boiling point
odor

23. Physical properties of matter are categorized as either Intensive or Extensive:
Intensive - Properties that do not depend on the amount of the matter present.
Color
Odor
Luster - How shiny a substance is.
Malleability - The ability of a substance to be beaten into thin sheets.
Ductility - The ability of a substance to be drawn into thin wires.
Conductivity - The ability of a substance to allow the flow of energy or electricity.
Hardness - How easily a substance can be scratched.
Melting/Freezing Point - The temperature at which the solid and liquid phases of a substance are in equilibrium at atmospheric pressure.
Boiling Point - The temperature at which the vapor pressure of a liquid is equal to the pressure on the liquid (generally atmospheric pressure).
Density - The mass of a substance divided by its volume

24. Physical properties of matter are categorized as either Intensive or Extensive:
Extensive - Properties that do depend on the amount of matter present.
Mass - A measurement of the amount of matter in a object (grams).
Weight - A measurement of the gravitational force of attraction of the earth acting on an object.
Volume - A measurement of the amount of space a substance occupies.
Length

25. Physical Changes Some physical changes would be boiling of a liquid
can be observed without changing the identity of the substance
Some physical changes would be
boiling of a liquid
melting of a solid
dissolving a solid in a liquid to give a homogeneous mixture — a SOLUTION.

26. Chemical Properties and Chemical Change
Burning hydrogen (H2) in oxygen (O2) gives H2O.
Chemical change or chemical reaction — transformation of one or more atoms or molecules into one or more different molecules.

27. Sure Signs of a Chemical Change
Heat
Light
Gas Produced (not from boiling!)
Precipitate – a solid formed by mixing two liquids together

28. Physical vs. Chemical physical Examples: melting point chemical
flammable
density
magnetic
tarnishes in air

29. Physical vs. Chemical chemical Examples: rusting iron physical
dissolving in water
burning a log
melting ice
grinding spices

30. Can it be physically separated?
Matter Flowchart
MATTER
yes no
Can it be physically separated?
MIXTURE
PURE SUBSTANCE
Is the composition uniform? no
yes
Can it be chemically decomposed? no
yes
Homogeneous Mixture
(solution)
Heterogeneous Mixture
Compound
Element
Colloids
Suspensions

31. Types of Mixtures Variable combination of 2 or more pure substances.
Heterogeneous – visibly separate phases
Homogeneous – Same throughout

32. Law of Definite Proportions
Joseph Proust (France 1799)
A given compound always contains elements in a certain proportion by mass. (Constant composition).

33. Percent Mass of Compounds
Atoms combine in whole number ratios, so their proportion by mass will always be the same.
Example: H2O is always made up of 2 atoms of H and one atom of O.
The mass ratio of O to H in water is always 16:2 or 8:1.
Percent Mass of Compounds
Percent composition consists of the mass percent of each element in a compound:
Percent by mass=

34. Example: KCl
KCl always contains one atom of K for every one atom of Cl
In KCl, potassium and chlorine always have a ratio of “39.09 to 35.45” or “1.1 to 1” by mass.

35. Law of Multiple Proportions (John Dalton)
When the same two elements combine to form more than one compound:
the ratios of the mass of one element in the first compound to its mass in the second compound, (as it combines with the same mass of the other element), can always be expressed as ratios of small whole numbers( ex: 1:3 or 2:5).

36. Example of Law of Multiple Proportions
Carbon combines with oxygen to form CO and CO2 .
Mass of Carbon(g)
Mass of Oxygen(g)
Ratio of O in CO2 to O in CO CO
CO2
12.01
16.00
2:1
12.01
32.00

37. Practice Problem 1
In the carbon compounds ethane (C2H6) and ethene (C2H4), what is the lowest whole number ratio of H atoms that react with the same number of C atoms?
Mass of Carbon (g)
Mass of Hydrogen (g)
Ratio of H in C2H6
to H in C2H4
C2H6
C2H4
24.02
6.06
6:4 or 3:2
24.02
4.04

38. Mixtures
Heterogeneous mixture – Uneven distribution of substances. You can see the different parts.
Examples:
Sand
Granite
Wood
Suspensions

39. Mixtures Homogeneous Mixture – Components are evenly mixed.
- Cannot see the parts.
Salt water contains salt and water, but are mixed all the way to the atomic level but it can still be separated by physical means.

40. Homogeneous Solutions Solute dissolves in solvent to form solution.
Concentrated solution contains more solute than dilute solution.
Small particle size (<2nm)
Can NOT be separated by filtration
Ex: Kool-Aid, iced tea, coffee

41. Solutions
A solution is a homogeneous mixture
A solute is the substance being dissolved
A solvent is dissolving the solute, most commonly a liquid (H2O)
Called an aqueous (aq) solution when solvent is H2O
Typically, the solute is the component in the smaller amount. Solvent is the component in the larger amount. 42

42. Types of Solutions Solution of gaseous solute in gaseous
solvent: Air (Oxygen & Nitrogen)
Solution of gas in liquid: Soft drinks (CO2
in water).
Solution of liquid in liquid: Nail polish
remover (acetone in water)
Solution of solid in liquid: Salt in water
Solution of solid in solid: Alloys such as
steel (a mixture of Fe & C).

43. Separation Methods: Filtration Distillation Crystallization
Sublimation
Chromatography

44. Filtration
Used to separate heterogeneous mixtures composed of solids & liquids
Uses a porous barrier (such as filter paper) that allows the liquid to pass through, but no the solid
Example: sand and water mixture

45. Distillation Used to separate homogeneous mixtures
Based on the differences in the boiling points of the involved substances
Mixture is heated until the substance with the lower boiling point boils to a vapor
The vapor is then condensed into a liquid and collected
Example: distilled water (removes minerals from the water)

46. Crystallization Used to separate substances in solution
Results in the formation of highly pure solids
As one substance evaporates, the dissolved substance comes out of solution and collects as crystals
Example: rock candy, salt water

47. Sublimation Used to separate mixtures of solids
One solid sublimes and the other is left behind
The gas can then be condensed and collected
Example: separating ammonium chloride (NH4Cl) from sand and salt

48. Chromatography
Used to separate components that are dissolved in a liquid or a gas
Based on the ability of each component to be drawn across the surface of another material
When the mixture is a liquid, it is drawn across chromatography paper
Separation occurs because the various components travel across the paper at different rates (the stronger attraction to the paper, the slower the rate)
Example: forensics: blood levels of toxins after a person’s death

49. What is a property? Describes a substance (matter)
Can be measured and/or observed
Some can be used to identify a substance
Chemical property Physical property
observed during a describes matter reaction

50. Intensive Properties of Pure Substances
remain the same when a substance changes in size
Some can be used to IDENTIFY a pure substance (density, boiling pt., melting pt.)
Apple floation demo (density)
Burn paper of different sizes
Fork vs. paperclip in outlet

51. Intensive Properties
If you can find it on a chart, it’s intensive

52. Extensive Properties of Pure Substances
Properties that are dependent on the amount of substance present (can be measured)
Can’t be used to identify
Mass, volume, & length

53. -depend on identity of substance -depend on amount of substance
Properties
Intensive
-depend on identity of substance
Extensive
-depend on amount of substance
Physical
Physical
Phase/state
Density
Luster
Malleability
Melting Pt.
Boiling Pt.
Conductivity
Brittleness
Specific Heat Capacity
Mass
Volume
Length
Weight

54. Physical Properties
Phase (state of matter): solid, liquid, gas, plasma
Luster: shiny
Malleable: can be pounded into sheets

55. Physical Properties…
Conductive: Ability to transfer thermal energy or electricity
Ductile: drawn into wire (metals)
Viscosity: resistance of a liquid
to flow

56. Physical Properties… Brittle: ability to break
Volatile: tendency for a substance to vaporize at normal (room) temperatures
Nonvolatile: doesn’t vaporize at normal (room) temperatures

57. Physical Properties that can identify a substance…
Density (D): relationship between the mass of a substance and how much space it takes up. (Does it sink or float in H2O?)
Specific Heat Capacity (C):
Amount of heat required to raise 1 g of water 1°C

58. Physical Properties that can identify a substance…
Melting Point/Freezing Point: temperature at which a substance melts & freezes
Boiling Point/Condensation Point:
temperature at which a substance boils & condenses

59. Physical Properties that are extensive…
Mass: how much matter in a substance (g or kg)
Volume: how much space the substance occupies (mL, L, cm3)
Length: how long something is (cm, m, km)

60. Chemical Properties
Number of valence e- - determines if & how a substance will react
Reactivity – tendency of a substance to react chemically

61. Chemical Properties…
Flammability – how easily a substance ignites or catches fire.
Combustibility – ability of a substance to burn.
Toxicity – ability of a substance to harm a living organism (humans)

62. Physical & Chemical Changes
All physical & chemical changes require ENERGY!

63. Physical Change
Physical Change – a change in the appearance of a substance but does NOT change its composition
Substances can be physically mixed together, but retain their own properties
Nitrogen gas (N2)
Oxygen gas (O2)
Mixture of gases (N2+O2) + =
Not sure if you want to go into this much detail

64. Ex. 1. Phase changes 2. Making a mixture Melting, boiling, sublimation
sublimation of I2
Freezing, condensing, deposition
2. Making a mixture

66. Chemical Change
Formation of a new substance with different properties that are observed
Substances chemically react & products have different properties than reactants.
Hydrogen gas (H2)
Oxygen gas (O2)
Water
(H2O) + =

67. Chemical Change
Formation of a new substance with different properties that are observed
Evidence of a Chemical Change:
1. Change in temperature
2. Production of a gas

68. 3. Permanent
color change when a new substance is made
4. Precipitate – formation of a solid product from 2 aqueous solutions reacting

69. Chemical Change Examples
Corrosion: breaking down of a metal through a chemical reaction
1. Rusting: reddish orange layer of corrosion over Fe
2. Tarnishing: black layer of corrosion over Cu, Ag, Al, Mg, etc.
Fermenting: converting of carbs to alcohols or acids using microorganisms
Photosynthesis

70. Physical & Chemical Changes Can Occur Simultaneously
Burning a candle
Eating candy
Weathering in nature
Combustion of wood
Have students discuss what the 2 types of changes are in each
burning of wood. The moisture present in the wood turns to vapor, when heated, which is a physical change. The actual burning of wood will generate carbon dioxide (among other products) and is a chemical change. 

71. Is melting ice a physical or chemical change?
Before After
Properties Before: Properties After:
Worksheet ex.
Are these properties intensive or extensive? Is the composition changing?

72. Are exploding fireworks a physical or chemical change?
Before After
Properties Before: Properties After:
Worksheet ex.
Are these properties intensive or extensive? Is the composition changing?

73. Ability to tarnish with air
Identify the following as either a physical property, a chemical property, a physical change, or a chemical change.
Water vaporizing
An old bike rusts
Has luster
Conducts electricity
Ability to explode
Photosynthesis
Crushing a soda can
Ability to tarnish with air
Physical change
Chemical change
Physical property
Physical property
Chemical property
Worksheet ex.
Chemical change
Physical change
Chemical property