1. Matter: Properties & Change
Chapter 3

2. Matter Matter – anything that has mass and takes up space
Everything around us
Chemistry – the study of matter and the changes it undergoes

3. Four States of Matter Solids particles vibrate but can’t move around
fixed shape
fixed volume
incompressible

4. Four States of Matter Liquids
particles can move around but are still close together
variable shape (shape of container)
fixed volume
virtually incompressible

5. Four States of Matter Gases
particles can separate and move throughout container
variable shape
variable volume
easily compressed
vapor = gaseous state of a substance that is a liquid or solid at room temperature

6. Four States of Matter Plasma
particles collide with enough energy to break into charged particles (+/-)
gas-like, variable shape & volume
stars, fluorescent light bulbs

7. Physical Properties Physical Property
can be observed without changing the identity of the substance

8. Physical Properties
Physical properties can be described as one of 2 types:
Extensive Property
depends on the amount of matter present (example: length)
Intensive Property
depends on the identity of substance, not the amount (example: density)

9. Chemical Properties Chemical Property
describes the ability of a substance to undergo changes in identity

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

11. Physical Changes Physical Change
changes the form of a substance without changing its identity
properties remain the same
Examples: cutting a sheet of paper, all phase changes

12. Phase Changes Evaporation = Condensation = Melting = Freezing =
Sublimation =
Deposition =
Liquid  Gas Gas  Liquid Solid  Liquid Liquid  Solid Solid  Gas Gas  Solid

13. Chemical Changes
Process that involves one or more substances changing into a new substance
Commonly referred to as a chemical reaction
New substances have different compositions and properties than the original substances

14. Chemical Changes Signs of a Chemical Change change in color or odor
formation of a gas
formation of a precipitate (solid)
change in temperature

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

16. Law of Conservation of Mass
Although chemical changes occur, mass is neither created nor destroyed in a chemical reaction
Mass of reactants equals mass of products
massreactants = massproducts
A + B C

17. Conservation of Mass GIVEN: WORK: 10.00 g = 9.86 g + moxygen
In an experiment, g of red mercury (II) oxide powder is placed in an open flask and heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26 g. What is the mass of the oxygen formed in the reaction?
GIVEN:
Mercury (II) oxide  mercury + oxygen
mmercury(II) oxide = g
mmercury = 9.86 g
moxygen = ?
WORK:
10.00 g = 9.86 g + moxygen
moxygen = (10.00 g – 9.86 g)
moxygen = 0.74 g
Mercury (II) oxide  mercury + oxygen
Mmercury(II) oxide = g
Mmercury = 9.26
Moxygen = ?
massreactants = massproducts

18. 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

19. Matter Flowchart Examples: graphite element pepper
sugar (sucrose)
paint
soda
element
heterogeneous mixture
compound
solution

20. Pure Substances Element composed of identical atoms
Example: copper wire, aluminum foil

21. Pure Substances Compound
composed of 2 or more elements in a fixed ratio
properties differ from those of individual elements
Example: table salt (NaCl)

22. Mixtures Variable combination of 2 or more pure substances.
Heterogeneous
Homogeneous

23. Mixtures Solution homogeneous very small particles
particles don’t settle
Example: rubbing alcohol

24. Mixtures Heterogeneous medium-sized to large-sized particles
particles may or may not settle
Example: milk, fresh-squeezed lemonade

25. Mixtures Examples: Answers: tea muddy water fog NaCl & H2O
Italian salad dressing
Answers:
Solution
Heterogeneous

26. Separating Mixtures
Substances in a mixture are physically combined, so processes bases on differences in physical properties are used to separate components
Numerous techniques have been developed to separate mixtures to study components
Filtration
Distillation
Sublimation
Crystallization
Chromatography

27. Filtration
Used to separate heterogeneous mixtures composed of solids and liquids
Uses a porous barrier to separate the solid from the liquid
Liquid passes through leaving the solid in the filter paper

28. Distillation Used to separate homogeneous mixtures
Based on differences in boiling points of substances involved

29. Sublimation
Process during which a solid changes to a vapor without melting
Can be used to separate two solids present in a mixture when one of the solids sublimates but the other does not

30. Crystallization
Separation technique that results in the formation of pure solid particles from a solution containing the dissolved substance
As one substance evaporates, the dissolved substance comes out of solution and collects as crystals
Produces highly pure solids
Rocky candy is an example of this

31. Chromatography
Separates components of a mixture based on ability of each component to be drawn across the surface of another material
Mixture is usually liquid and is usually drawn across chromatography paper
Separation occurs because various components travel at different rates
Components with strongest attraction for paper travel the slowest; components with strongest attraction for the liquid travel the fastest

32. Separation of a Compound The Electrolysis of Water
Compounds must be separated by chemical means.
With the application of electricity, water can be separated into its elements
Reactant  Products
Water  Hydrogen + Oxygen
2 H2O  H O2