Modified True/False
Indicate
whether the sentence or statement is true or false. If false, change the identified word or
phrase to make the sentence or statement true.
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1.
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Water
is not very good for dissolving ionic compounds. ____________________
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2.
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Parts
per million is a concentration unit that is used to express very large concentrations of ions
in solution. ____________________
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3.
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Drinking water contains dissolved iodide ions to kill bacteria.
____________________
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4.
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The
quantity of oxygen dissolved in a body of fresh water is directly related to the health of the
aquatic ecosystem. ____________________
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5.
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Boiling water is an effective way to soften water.
____________________
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6.
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Warm
lake water will contain more dissolved oxygen than cold lake water.
____________________
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Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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7.
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Which
of the following compounds does not dissolve very well in water? a. | sodium
chloride | c. | alcohol | b. | sugar | d. | gasoline | | | | |
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8.
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An
underground formation that collects and stores water is a(n) a. | puddle | c. | aquifer | b. | reservoir | d. | pond | | | | |
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9.
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Which
of the following substances is a common source of water contamination? a. | agricultural
fertilizers | c. | agricultural
pesticides | b. | road salt runoff | d. | all of the above | | | | |
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10.
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The
contamination of Walkerton’s water supply in 2000 was caused by a. | lead | c. | pesticides | b. | mercury | d. | E. coli bacteria | | | | |
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11.
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Which
of the following chemical substances is used to form a sticky precipitate that helps to clear murky
water? a. | household
ammonia | c. | aluminum
sulfate | b. | alum | d. | all of the above | | | | |
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12.
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Which
of the following ions, if found in large concentrations in a freshwater source, causes the water to
be “hard”? a. | magnesium, Mg | c. | nitrate, NO | b. | sulfide, S | d. | sodium, Na | | | | |
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13.
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Water
is classified as “moderately hard” if the concentration of hard water ions
is a. | 50–200
ppm | c. | <50
ppm | b. | 200–400
ppm | d. | >400
ppm | | | | |
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Completion
Complete each sentence or
statement.
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14.
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The
physical properties that you could measure to identify pure water are ____________________,
____________________, and ____________________.
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15.
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If a
sports drink contains 50 mg of sodium ions per 500 mL, the concentration of sodium ions, in ppm, is
____________________.
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16.
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Fertilizers used in agricultural applications are the main source of
____________________ and ____________________ ions that contaminate Great Lakes fresh
water.
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17.
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The
presence of certain ions in a water sample can be determined by adding a test chemical and observing
the formation of a ____________________.
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18.
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A
particular type of light, ____________________, is quite effective at destroying biological
contaminants in water.
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19.
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A
two-step process of evaporation and condensation that is used to purify water is called
____________________.
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