Chapter 7 Review
Answer Section
MODIFIED TRUE/FALSE
1. ANS: F
Vegetable soup is an example of a heterogeneous mixture.
2. ANS: F
The liquid must be a solution.
3. ANS: T
4. ANS: T
5. ANS: T
6. ANS: F
All solutions are homogeneous mixtures.
7. ANS: T
8. ANS: T
9. ANS: F
A beam of light will not scatter as it passes through a solution. If light scatters, the mixture is not
completely dissolved, and is not a solution.
10. ANS: T
A mixture that has the same set of properties throughout is a homogeneous mixture, that is, a
solution.
11. ANS: T
12. ANS: F
Solutions can also form when gases or liquids dissolve in solids, liquids or gases.
13. ANS: F
Sugar water is an example of a homogeneous mixture, that is, a solution.
14. ANS: F
A stick of chalk, calcium carbonate, is an example of a pure substance.
15. ANS: F
Sugar is an example of a pure substance.
MULTIPLE CHOICE
16. ANS: A
COMPLETION
17. ANS: homogeneous
18. ANS: heterogeneous
19. ANS: alloy
20. ANS: gas
21. ANS: pure substance
22. ANS: pure
23. ANS: property
24. ANS: heterogeneous
25. ANS: homogeneous mixture
26. ANS: solution
27. ANS: solution
28. ANS: heterogeneous mixture
29. ANS: solvent, solute
30. ANS: filtration
31. ANS: heterogeneous
MATCHING
32.
33.
34.
35.
36.
37.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
B
B
C
A
C
D
38.
39.
40.
41.
42.
43.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
B
B
C
B
C
SHORT ANSWER
44. ANS:
Smoky air is a heterogeneous mixture. The air is a solution, and the smoke particles are solids.
When light passes through clean air, the particles of gas are too small to scatter light. The solid
smoke particles in smoky air are large enough to scatter light, so you see a beam of scattered light.
45. ANS:
Responses will vary. Possible examples are:
solid state — alloys such as steel (carbon in iron); bronze (tin in copper); brass (zinc in copper);
solder (silver in tin)
liquid state — vinegar (acetic acid in water); liquid honey (sugar in water); corn syrup (glucose in
water)
gas state — air (oxygen in nitrogen); anesthetics (ether in air); odours (perfume in air); welding
gases (acetylene in oxygen)
46. ANS:
A pure substance is composed of only one kind of particle throughout (e.g., distilled water, white
sugar, 24 carat gold, medical oxygen).
A mixture is composed of at least two different kinds of particles throughout (e.g., soft drink, salt
water.)
47. ANS:
a) mixture; b) mechanical mixture; c) homogeneous; d) solution.
48. ANS:
You could add any substance that will not dissolve (e.g., pepper, or oil). The particles of acetic acid
and water are different from each other, and they are evenly distributed throughout the solution.
When you add the new substance, its particles do not mix in with the others. There are now visibly
different kinds of matter in the measuring cup. In each kind of matter, the particles are different.
49. ANS:
a) Mixtures of this sort are heterogeneous mixtures. There are two or more different kinds of matter
visible in the mixture. The solid bits are denser than the liquid. If left for a few hours, the solid bits
tend to sink to the bottom.
b) The solid bits generally contain the medicine. If you just take the liquid part, you are not getting
the medicine you need. Shaking redistributes the substances in them evenly.
ESSAY
50. ANS:
Soil is made up of fine clay particles, bits of organic matter such as decaying plants and insects,
sand, and silt, or small particles of rock. Pure substances, such as iron or calcium carbonate, may be
present in soil, but they are part of a mixture of different particles.
51. ANS:
Student answers will vary. A heterogeneous mixture is made up of two or more parts. Often, you can
see the different parts just by looking at the mixture. Concrete and salad are examples of
heterogeneous mixtures. A homogeneous mixture is one in which the parts appear to be the same
throughout. Sugar-water and alloys are examples of homogeneous mixtures.