Chapter 8 Review
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
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1. As water evaporates from a solution of salt and water, the concentration of salt decreases.
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2. A concentrated solution contains a low mass of solute for a certain volume of solvent.
_____________________________________________________________
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3. A solute dissolves more slowly when the mixture is stirred.
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4. Under normal conditions, a saturated solution can still dissolve more solute.
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5. Solidified honey contains some water and a lot of sugar crystals. Solidified honey is an unsaturated
solution.
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6. The attraction between sugar and water particles in a solution of sugar and water is weaker than the
attraction between sugar and sugar particles in solid sugar.
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7. A substance is soluble in a solvent when it dissolves in the solvent.
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8. The size of sugar pieces does not affect the rate at which the sugar dissolves in water.
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9. Breaking a solute into smaller pieces makes it dissolve faster because the particles move faster.
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____ 10. One cup of salt was added to a plastic bottle of pure water, and sealed. One year later, some salt
could still be visible on the bottom of the bottle. This is an example of an unsaturated solution.
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____ 11. At higher water temperatures, the solubility of sugar decreases, but the solubility of carbon dioxide
increases.
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Completion
Complete each statement.
12. The substance in which a solute dissolves is called the ____________________.
13. Usually, to make a dilute solution, you would dissolve a ___________ quantity of solute in a
__________ quantity of solvent.
14. If you have a concentrated solution, you can make a dilute solution by adding more
____________________.
15. The quantity of solute that is dissolved in a certain quantity of solvent is known as the
____________________ of the solution.
16. The maximum mass of a substance that will dissolve in 100 g of water at a certain temperature is
called the ____________________.
17. When an unsaturated solution is heated and some solvent is lost, the solution becomes more
___________________.
18. The rate at which a solute dissolves in a solvent can be increased by ___________________ and
___________________.
19. You have a clear solution. You add one more crystal of solute to it, and the crystal dissolves. The
original solution was ___________________.
20. Imagine that you start with a clear solution at 30°C, and cool it to observe a clear solution at 10°C.
Besides the temperature, the only property of the solution that changed was the
____________________.
21. When a saturated solution of sugar in water is gently heated, it will become ______________.
22. A saturated solution of baking soda in water is at 30°C. The mixture is cooled to 10°C. The
concentration of the baking soda solution will _________________.
23. A student mixes some pure water and some pure ice together, and stirs until the ice has completely
disappeared. The resulting liquid is a(n) _______________________.
24. Fog is best described as a _____________________________ of water in air.
25. You have a sealed bottle of sugar and water. Inside the sealed bottle, as the solution is heated, the
________________ of the sugar increases.
26. When you open a bottle of soda water, bubbles of carbon dioxide “fizz” appear. The
_____________ of dissolved carbon dioxide is decreasing.
Matching
Match the term with an appropriate description. Each term may be used more than once.
a. saturated
b. unsaturated
____ 27. A crystal added to the solution dissolves.
____ 28. A crystal added to the solution will not dissolve.
____ 29. When the solution is cooled, no excess solute is seen.
____ 30. Lumps of undissolved solid are seen at the bottom of the solution.
____ 31. The solution has dissolved as much solute as it can at a certain temperature.
Match the term with an appropriate description. Each term is only used once.
a. saturated
e. dissolves
b. solvent
f. solute
c. solubility
g. insoluble
d. concentration
h. dilute
____ 32. a substance in which a solute dissolves
____ 33. a solution that can dissolve no more solute
____ 34. the quantity of solute that is dissolved in a certain quantity of solvent
____ 35. the maximum mass of a substance that will dissolve in 100 g of water at a certain temperature
____ 36. a solute does this in solvent
____ 37. usually has a smaller mass of solute for a certain volume of solvent
____ 38. substance that cannot dissolve
____ 39. substance that dissolves
Short Answer
40. Why does stirring a solution of water and sugar increase the rate at which sugar dissolves?
41. Using one sentence for each, describe three ways you could dissolve a solid solute in a liquid solvent
more quickly.
42. Using one sentence each, describe two ways to dissolve more gas into a liquid.
43. The diagrams below show a solid solute (black) mixed with a liquid solvent (white). In which of
these situations will the solute dissolve faster? Explain why this would happen.
44. Tracey and Alyssa were experimenting with tea bags in hot and cold water. Tracey placed a tea bag
in a mug of hot water, while Alyssa placed a second bag into a mug of cold water. Both tea bags
were moved up and down eight times, and then removed.
a) Predict the colour of the tea in the two cases.
b) Explain any differences using the particle theory.
45. As a lab assignment, students were given a salt and water solution and asked to determine if the
solution was saturated or unsaturated. How could they do this? How would they know?
46. Matt is making some iced tea using a powdered mix. Matt prefers strong iced tea. Is there a limit to
how strong Matt can make his tea? Explain your answer using the particle theory.
47. While making stew, you read that the recipe calls for bouillon, either cubes or powder. You are in a
hurry. Which will be faster to use? Why?
Essay
48. During a lab investigation, students found that 3.2 g of a certain substance dissolves in 10 mL of
water at 20°C.
a) What is the solubility of the substance, in g/L ? Show your calculation.
b) Students then heated the solution to 30°C and found that 0.6 g more of the solute would dissolve.
What would the solubility of this substance be then, in g/L? Show your calculation and explain what
is occurring.