ChemQuest 8
Name: _______________________
Date: _______________
Information: Elements, Compounds, Mixtures
Examine the following tables. Following the name of each element or compound is the
“chemical formula” of the element or compound; please see the periodic table for the
meaning of some of the symbols (i.e. Na = sodium). Italics tell you that substance is organic.
Elements
Sodium (Na)
Chlorine (Cl)
Carbon (C)
Oxygen (O)
Hydrogen (H)
Compounds
Water (H2O)
Methane (CH4)
Sodium chloride, salt (NaCl)
Carbon dioxide (CO2)
Hydrogen Peroxide (H2O2)
Pure Substances
Salt (NaCl)
Hydrogen (H)
Carbon dioxide (CO2)
Water (H2O)
Aluminum (Al)
Mixtures
Salt water (NaCl and H2O)
Sand
Hydrogen (H) and Oxygen (O)
Sodium (Na) and Chlorine (Cl)
Kool-aid (sugar, water, etc.)
Critical Thinking Questions
1. How are elements different from compounds?
2. How are compounds different from mixtures?
3. How are pure substances different from mixtures?
4. Can something be both a mixture and a pure substance? Explain using examples from
the tables.
5. Is it always possible to identify something as an element, compound, pure substance
or mixture just by looking at it? Explain using examples from the tables.
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6. Formulate a definition for each of the following terms.
a) element:
b) compound:
c) mixture:
d) pure substance:
7. Categorize each of the following as an element, compound, mixture, or pure
substance. If more than one label applies, then include both labels. (You will need
more than one label sometimes.)
a) ___________________ Popsicle
c) _____________________ Gold
b) ___________________ Sugar
d) _____________________ Dishwater
8. If you have a container with hydrogen gas and oxygen gas in it do you have water?
Why or why not?
9. Give an example of something that is an element. Your example should not already be
on this sheet.
10. Give an example of something that is a compound. Your example should not already
be on this sheet.
11. Give an example of something that is a mixture. Your example should not already be
on this sheet.
12. What do all organic substances have in common?
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Information: Homogeneous and Heterogeneous Mixtures
Examine the following table.
Example of Mixture
Salt water
Oil and water
Sugar and salt (no water)
Sugar and salt in water
Sand and water
Carbon dioxide, water, and ice
14 kt. gold (mixture of silver
and gold)
# of phases in
mixture
1
2
2
1
2
3
1
How many kinds of
states in mixture
2
1
1
2
2
3
1
Homogeneous or
heterogeneous?
Homogeneous
Heterogeneous
Heterogeneous
Homogeneous
Heterogeneous
Heterogeneous
Homogeneous
Critical Thinking Questions
13. What is the difference between a "phase of matter" and a "state of matter"? Define
each term as best you can.
14. What relationship exists between a homogeneous mixture and the number of phases
in the mixture?
15. What is the difference between homogeneous and heterogeneous mixtures?
16. If you had to categorize elements as homogeneous or heterogeneous, what category
would you put them in?
17. If you had to categorize compounds as homogeneous or heterogeneous, what category
would you put them in?
18. Categorize each of the following as homogeneous or heterogeneous.
_____________ a) salad
________________ b) ice water
_____________ c) dishwater
________________ d) 14 kt. Gold
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Skill Practice 8
Name: ______________________________
Date: _______________
1. Explain why compounds are always homogeneous, but mixtures can be either
homogeneous or heterogeneous.
2. A white powder is in a beaker. Which statement(s) can be said for sure about the
powder?
I.
It is homogeneous
II.
It is heterogeneous
III.
It is a mixture.
IV.
It is a compound.
A) I only
of these
B) I and IV only
C) I and III only
D) III only
E) none
3. Classify the following as chemical changes (C) or physical changes (P). Place a C or P in
the blanks as appropriate.
_____ d) melting steel
_____ a) a dead fish rotting
_____ e) bending steel
_____ b) dissolving salt in water
_____ f) cracking ice
_____ c) boiling salt water until just salt remains
4. Identify the following as an element (E), compound (C), or mixture (M).
_____ a) calcium
_____ d) water
_____ b) calcium and oxygen in the same container
_____ e) sodium
_____ c) calcium and oxygen atoms bonded
_____ f) sand
5. How many phases and how many states are in a mixture made out of sand, saltwater, oil
and ice?
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