Section A Sources and Uses of Water
1) Definitions (Look 'Em Up Yourself)
2)
(a) d
(b) i -- Water is used to grow the fruit, to can the fruit, to mine the metal in the cans, to grow the trees for the paper in label, to get the product to market, etc.
(c) i --Water is used to raise the cow, butcher the cow, grow the grain for the bun, raise the vegetables (lettuce, tomatoes, etc.) and ship the items to the restaraunt.
(d) d
| 3) | iii, i | 4) | Steam-Electric | Steam-Electric |
| ii, ii | Steam-Electric | Irrigation | ||
| iv, iv |
| 5) | Ocean | Glaciers and Ice Caps | 0.0001 % |
| 0.62 % | an Aquifer | Solid |
19 L - 9 L = 10 L per minute . . . 10 L per min x 30 minutes per day = 300 L per day . . . 300 L per day x 7 days per week = 2100 L per week
Section B A Look at Water and Its Contaminants
1) Definitions (Look 'Em Up Yourself)
| 2(a) |  |
(b) |  |
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Element |
Compound |
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| (c) |  |
 |
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Solid |
Liquid |
Gas |
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| (d) |
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| 3) |
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Reactants . . . . . . . . . . . . . . . . . . . . . . . Products |
Symbol
Atom, Cation, or Anion
# Protons
# Electrons
F
Atom
9
9
F -
Anion
9
10
Mg
Atom
12
12
Mg 2+
Cation
12
10
Al 3+
Cation
13
10
O 2-
Anion
8
10
| 5) | Names of Compounds | 6) | Formulas of Compounds |
| (a) | Potassium Nitrate | (a) | NaF |
| (b) | Calcium Iodide | (b) | BaBr2 |
| (c) | Aluminum Sulfate | (c) | Ag2SO4 |
| (d) | Ammonium Hydroxide | (d) | Al(NO3)3 |
Section C Investigating The Cause of the Fish Kill
1) Definitions (Look 'Em Up Yourself)
| 2) | (a) | The solubilibty is about 28 g per 100 g of water |
| (b) | Nope. The maximum you can normally dissolve would be about 32 g in 100 g of water. | |
| (c) | It is unsaturated. It looks like it could dissolve 11 or 12 g in 100 g of water. | |
| (d) | You could dissolve about 7.5 g of C in 25 g of water. (Use an equivalent fraction.) | |
| (e) | About 50 g of water could dissolve 30 g of substance A at 60 oC. (Use an equivalent fraction.) | |
| (f) | Substance C must be a gas since its solubility decreases as temperature increases. |
| 3) | ||
| (a) | (b) | (c) |
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| 4(a) | Heavy Metals |
Uses |
Health Effects |
| Lead (Pb) | Pottery, Car Batteries, Solder, Pesticides, and Paints | Heavy metalsbind to proteins, damaging kidneys, liver, nervous system, and the brain. | |
| Mercury (Hg) | Light Switches, Lamps, Lights, Paints | See Above. |
| 4(b) |
Type of Substance |
Examples |
pH |
Effect on Fish Health |
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Acids |
Stomach Acid Soft Drinks Coffee |
1 3 5 |
Too much acid causes egg development impaired and heavy metals to leach out of soils. |
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Bases |
Drain Cleaner Ammonia Sea Water |
14 12 8 |
Basic solutions can dissolve organic materials including skin and scales. |
| 4(c) | (i) Urea, sodium chloride, and ethanol are polar. | (ii) Iodine and perhaps ethanol is a molecular solute. |
| (iii) The mystery solute is nonpolar because it acts like lamp oil. | (iv) The phrase is "Like dissolves like." |
| 4(d) | Two factors that affect the solubility of oxygen in water are temperature and pressure. As temperature increases, solubility decreases. As pressure increases, solubility increases. |
| 4(e) | High water temperatures, the presence of pollution, and competition from other oxygen using organisims in the water can cause low dissolved oxygen levels in water. |
| 4(f) | The supersaturation of nitrogen gas can occur in the froth that occurs at the base of dams. |
Section D Water Purification and Treatment
1) Definitions (Look 'Em Up Yourself)
| 2) | (a) | Dissolved substances are removed during evaporation. | |
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Bacteria decompose organic matter after precipitation as water seeps below the soil surface. | ||
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Filtration occurs after precipitation as water seeps through sand and gravel. | ||
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Atmospheric gases dissolve in water vapor after evaporation. |
| (e) | Small suspended particles are removed during flocculation. | ||
| (f) | Pre-chlorination kills bacteria and diseases in the beginning of the treatment process. | ||
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Alum and slaked lime are added during flocculation. | ||
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Screening removes large objects from water. | ||
| (i) | Post-chlorination adjusts the level of chlorine to kill residual bacteria and diseases at the end of the treatment process. |
| 3) | (a) | Chlorination can occur by adding chlorine gas, sodium hypochlorite, or calcium hypochlorite. | |
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Trihalomethanes can cause cancer. | ||
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Activated charcoal can filter out THMs. Ozone can replace chlorine. The pre-chlorination step can be eliminated |
| 4) | (a) | Calcium, iron, and magnesium ions cause hardness. | |
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Hard water can depresses detergent action, cause bad taste, and form deposits in plumbing. | ||
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Water softeners replace calcium, iron, and magnesium ions with sodium ions. |