1. Pure Substances vs. mIXTURES
PENTONEY 2016

2. What is a pure substance?
A pure substance is a classification of matter that includes elements, molecules and compounds
Pure substances cannot be separated by physical means such as distillation, filtration, or sifting.

3. CHEMISTRY: MIXTURES AND PURE SUBSTANCES
Element
Molecule
Compound
Not one of those? NOT A PURE SUBSTANCE!

4. CHEMISTRY: MIXTURES AND PURE SUBSTANCES
ELEMENT:
One or more of the same type of atom.
Ex: N N2
Both of these examples are called an element as we only have the element Nitrogen (N) and nothing else.

5. CHEMISTRY: MIXTURES AND PURE SUBSTANCES
COMPOUND:
Two or more atoms chemically combined, at least one is different.
Ex: CO2 (Carbon Dioxide) NaCl (salt)
Both of these examples are types of compounds.

6. CHEMISTRY: MIXTURES AND PURE SUBSTANCES
MOLECULE: 2 or more atoms chemically combined.
Ex: N2 N3 H2O

7. *CHEMISTRY: MIXTURES AND PURE SUBSTANCES
Ex: N2 N3 (The first 2 examples of a molecule are more specifically called an “Element” because they are made up of only 1Type of atom.)

8. *CHEMISTRY: MIXTURES AND PURE SUBSTANCES
Ex: H2O
(This 3RD example is also a molecule, as it has 2 or more atoms combined. But a more specific name for this type of molecule, is a compound. )

9. CHEMISTRY: MIXTURES AND PURE SUBSTANCES
The words “ELEMENT” and “COMPOUND” are specific types of molecules.

10. *All of the boxes below show an example of a pure substance
ELEMENT (C) MOLECULE (O2) COMPOUND (CO2)

11. CHEMISTRY: Mixtures and Pure substances
Examples of pure substances:
Salt (NaCl)
Sugar
H2O (Water)
C6H12O6 (Glucose = Sugar)
ELEMENTS (like gold, silver, oxygen, nitrogen…any on the periodic table)

12. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
MIXTURE: two or more pure substances thrown together. All substances keep their own identities.
*Example: When I mix sugar and water, I get the mixture sugar-water. The sugar still has its own identity (it is sweet), the water still has its own identity (its still water). Nothing new is created, and both can be separated physically (boiling).

13. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
There are two types of mixtures:
Homogenous
Heterogeneous

14. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
Homogenous Mixture: Evenly mixed mixture
Examples:
Milk
Air (a mixture of gases you breath in)
Soda
Juice

15. What Is a Homogenous Mixture?
A mixture that is evenly distributed
Commonly called solutions.
Solution = Solute + Solvent
Solute: “stuff” being dissolved
Solvent: “stuff” doing the dissolving
The solvent is present in greater quantity
The solute is present in the lesser quantity
Ex: Salt water: Salt = solute, Water = solvent
NEED to know what solutions are: when something is dissolved in something else

16. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
Heterogeneous Mixture: Unevenly mixed mixture.
Example:
Salad
Legos
Cookie dough ice-cream
Chicken noodle soup

17. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
ALL MIXTURES ARE PHYSICALLY COMBINED AND CAN BE PHYSICALLY SEPARATED.

18. CHEMISTRY: MIXTURES AND PURE SUBSTANCE
Ways to physically separate a mixture:
Boiling: evaporates liquid
Sifting: Picking out pieces (like in cookies dough ice-cream =) )
Filtering: Just like a pool filter, it takes out unwanted things.

19. *CHEMISTRY: MIXTURES AND PURE SUBSTANCE
What is the biggest differences between a mixture and a pure substance?
Mixtures
Pure substance
Are physically mixed together
Chemically combined (bonded)
Can be physically separated
Must be chemically separated

20. Classifying Matter Matter Pure Substances Mixtures milk, tea Fe, O Fe2
Homogeneous
Heterogeneous
Copy the ENTIRE chart!
Elements
Compounds
Rocky Road ice cream, muddy water
milk, tea
Molecules
Fe, O
Fe2
H2O, CO2

21. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 1: Which substance is not a compound? a. Ne c. SiO2 b. HCN d. H2O2

22. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 1: Which substance is not a compound? a. Ne c. SiO2 b. HCN d. H2O2

23. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 2: The components of a homogeneous mixture could be described as a. inseparable c. chemically bonded b. evenly mixed d. unevenly mixed

24. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 2: The components of a homogeneous mixture could be described as a. inseparable c. chemically bonded b. evenly mixed d. unevenly mixed

25. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 3: Iron filings are thrown into a pile of sand. What is the best way to separate this mixture? A. Use a magnet to pick up the sand. B. Sift through the sand for all of the iron. C. Use a magnet to pick up the iron filings.

26. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 3: Iron filings are thrown into a pile of sand. What is the best way to separate this mixture? A. Use a magnet to pick up the sand. B. Sift through the sand for all of the iron. C. Use a magnet to pick up the iron filings.

27. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 4: A substance contains two components joined by physical means. Which best describes the substance? A. element B. compound C. mixture D. molecule

28. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 4: A substance contains two components joined by physical means. Which best describes the substance? A. element B. compound C. mixture D. molecule

29. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 5: Which best describes water? A. a compound B. an element C. a heterogeneous mixture D. a homogeneous mixture

30. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 5: Which best describes water? A. a compound B. an element C. a heterogeneous mixture D. a homogeneous mixture

31. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 6: Which image below is a mixture? A B C D

32. CHEMISTRY: MIXTURES AND PURE SUBSTANCE REVIEW
Question 6: Which image below is a mixture? A B C D Element Compound molecule mixture of elements + compounds