1. Section 3.3 Mixtures of Matter
Contrast mixtures and substances.
Classify mixtures as homogeneous or heterogeneous.
List and describe several techniques used to separate mixtures.
substance: a form of matter that has a uniform and unchanging composition; also known as a pure substance
Section 3-3

2. Section 3.3 Mixtures of Matter (cont.)
heterogeneous mixture
homogeneous mixture
solution
filtration
distillation
crystallization
sublimation
chromatography
Most everyday matter occurs as mixtures—combinations of two or more substances.
Section 3-3

3. Homogeneous mixtures are also called solutions. Examples…
A mixture is a physical combination of two or more pure substances in which each pure substance retains its individual chemical properties.
A homogenous mixture is a mixture where the composition is constant throughout.
Homogeneous mixtures are also called solutions.
Examples…
Section 3-3

4. Solution homogeneous very small particles no Tyndall effect
particles don’t settle
EX: rubbing alcohol
C. Mixtures

5. Mixtures (cont.)
Section 3-3

6. mixture is not uniform in composition Examples…
Mixtures (cont.)
A heterogeneous mixture is a mixture where the individual substances remain distinct.
mixture is not uniform in composition
Examples…
Section 3-3

7. Colloid heterogeneous medium-sized particles Tyndall effect
particles don’t settle
EX: milk
C. Mixtures

8. Suspension heterogeneous large particles Tyndall effect
particles settle
EX: fresh-squeezed lemonade
C. Mixtures

9. Examples: colloid mayonnaise suspension muddy water fog solution
saltwater
Italian salad dressing
C. Mixtures

10. Separating Mixtures
Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.
Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances.
Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance.
Section 3-3

11. Separating Mixtures (cont.)
Sublimation is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not.
Chromatography is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material.
Section 3-3

12. A B C D Section 3.3 Assessment
Which is NOT a technique for separating a homogenous mixture?
A. crystallization
B. distillation
C. filtration
D. chromatography A B C D
Section 3-3

13. A B C D Section 3.3 Assessment
Which of the following is a heterogeneous mixture?
A. seawater
B. silver mercury amalgam
C. atmosphere
D. salad dressing A B C D
Section 3-3

14. Section 3.4 Elements and Compounds
Distinguish between elements and compounds.
Describe the organization of elements in the periodic table.
Explain how all compounds obey the laws of definite and multiple proportions.
proportion: the relation of one part to another or to the whole with respect to quantity
Section 3-4

15. Section 3.4 Elements and Compounds (cont.)
periodic table
compound
law of definite proportions
percent by mass
law of multiple proportions
A compound is a combination of two or more elements.
Section 3-4

16. 92 elements occur naturally on Earth.
An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.
92 elements occur naturally on Earth.
Each element has a unique name and a one, two, or three-letter symbol.
The periodic table organizes the elements into a grid of horizontal rows called periods and vertical columns called groups.
Section 3-4

17. A compound is a made up of two or more elements combined chemically.
Compounds
A compound is a made up of two or more elements combined chemically.
Most of the matter in the universe exists as compounds.
Table salt, NaCl, and water, H2O, are compounds.
Section 3-4

18. Elements can never be separated.
Compounds (cont.)
Elements can never be separated.
Compounds can be broken into components by chemical means.
Section 3-4

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

20. Law of Definite Proportions
The law of definite proportions states that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample.
Section 3-4

21. Law of Definite Proportions (cont.)
The relative amounts are expressed as percent by mass, the ratio of the mass of each element to the total mass of the compound expressed as a percentage.
Section 3-4

22. Law of Definite Proportions (cont.)
This table demonstrates that the percentages of elements in sucrose remain the same despite differences in sample amount.
Section 3-4

23. Law of Multiple Proportions
The law of multiple proportions states that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in whole number ratios.
H2O2 and H2O
Copper(I) chloride and copper(II) chloride
Section 3-4

24. Law of Multiple Proportions (cont.)
Section 3-4

25. A B C D Section 3.4 Assessment
What is a period on the periodic table of the elements?
A. a vertical columns
B. even numbered elements only
C. horizontal rows
D. the last vertical column only A B C D
Section 3-4

26. A B C D Section 3.4 Assessment
An element is a substance that cannot be
A. divided into simpler substances.
B. combined to form a mixture.
C. combined to form an element.
D. different phases. A B C D
Section 3-4