1. compound
2. solubility
3. suspension
4. element
5. nonmetal
6. solute
7. C
8. B
9. C
10. B
11. C
12. A
13. C
14. A
15. Elements
cannot be separated into simpler substances, but compounds can be separated by
chemical means.
16. Nail polish
is the solute, and acetone is the solvent.
17. 50 g/200 mL = 0.25 g/mL
18. 150 mL ´ 0.6
g/mL = 90 g
19.
20. Carbonated
beverages should be stored in a refrigerator. Gases are more soluble at lower
temperatures, so more gas will stay dissolved in the beverage if it is kept
cold.
21. The powder
is a compound. The change in color and the formation of a gas imply that a
chemical change took place. Compounds can be broken down by chemical changes.
22. The exact
concentration tells you exactly how much solute is dissolved in the solvent. Concentrated
and dilute are descriptive terms that do not tell you the amount of
solute.
23. Sample
answer: Pass the mixture through a screen that allows the salt and pepper to
pass through but traps the pebbles. Mix the salt and pepper with water to
dissolve the salt. Filter the mixture to trap the pepper. Evaporate the water
to recover the salt.
24. (Teacher’s
Note: The graph should have “dissolved solute” on the y-axis and
temperature on the x-axis. The curve will decrease from left to right.)
You should decrease the temperature to increase the solubility. As the
temperature decreases, more solute can dissolve.
25. 68 g
26. Because the
solubility increases as the temperature decreases, the solute is most likely a
gas.
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