Oceanography Questions
Duxbury Chapter 6

  1. What is a positively-charged atom called?
    Anion
    Cation
    Compound
    Element
    Isotope

  2. What is the basis of ionic bonding?
    Peculiar combinations of protons and neutrons in the atomic nucleus
    The free flow of electrons between atoms
    The polar structure of certain molecules
    The sharing of electrons between adjacent atoms
    The transfer of one or more electrons from one atom to another

  3. Which of the following forms an anion?
    Calcium
    Chlorine
    Magnesium
    Potassium
    Sodium

  4. What is the most abundant dissolved ion in the oceans?
    Calcium
    Chlorine
    Magnesium
    Potassium
    Sodium

  5. What value is salinity usually measured in?
    Calories
    Ounces
    Parts per million
    Parts per thousand
    Percent

  6. What is a typical approximate chlorine concentration in sea water?
    10
    15
    20
    25
    35

  7. What is a typical salinity value for the oceans?
    10
    15
    20
    25
    35

  8. How do the relative proportions of dissolved ions differ throughout the oceans?
    The Atlantic ocean has a higher relative concentration of trace elements than the other oceans.
    The Pacific ocean has a higher relative concentration of trace elements than the other oceans.
    The polar regions have lower relative concentrations of complex ions.
    The tropical regions have lower relative concentrations of complex ions.
    There is almost no variation in relative proportions throughout the oceans.

  9. Where does ocean salinity tend to be the highest?
    At desert latitudes
    In deeper water
    Near river mouths
    Near the equator
    Near the poles

  10. Which of the following is not one of the six most abundant ions in seawater?
    Magnesium
    Potassium
    Silicon
    Sodium
    Sulfate

  11. Which of these ions has the shortest residence time in the oceans?
    Aluminum
    Calcium
    Potassium
    Sodium
    Sulfate

  12. What is the formula for bicarbonate ion?
    CO3-
    CO32-
    HCO3-
    HCO32-
    SO42-

  13. Which salt tends to precipitate first as seawater evaporates to increase the ion concentration?
    Calcite (CaCO3)
    Fluorite (CaF2)
    Gypsum (CaSO4)
    Halite (NaCl)
    Sylvite (KCl)

  14. Which salt precipitates in the greatest mass when seawater is completely evaporated?
    Calcite (CaCO3)
    Fluorite (CaF2)
    Gypsum (CaSO4)
    Halite (NaCl)
    Sylvite (KCl)

  15. What is the most abundant gas dissolved in ocean surface water?
    Argon (Ar)
    Carbon dioxide (CO2)
    Helium (He)
    Nitrogen (N2)
    Oxygen (O2)

  16. What is the most abundant gas dissolved in ocean water overall?
    Argon (Ar)
    Carbon dioxide (CO2)
    Helium (He)
    Nitrogen (N2)
    Oxygen (O2)

  17. Why is the oxygen level low (<2mL/L) in deep ocean water?
    Lack of oxygen solubility in cold water
    Lack of oxygen solubility in warm water
    Lack of sunlight for photosynthesis
    Low animal biomass
    Precipitation in ocean sediments

  18. What is the pH of pure water?
    5
    6
    7
    8
    9

  19. What is the typical pH of seawater?
    5
    6
    7
    8
    9

  20. What is the overall effect of carbon and its chemical reactions on seawater?
    It buffers the pH.
    It lowers the pH.
    It lowers the temperature.
    It raises the pH.
    It raises the temperature.

  21. What forms when carbon dioxide mixes with seawater?
    Calcite (CaCO3)
    Carbonic acid (H2CO3)
    Ethanol (C2H6O)
    Methane (CH4)
    Sugar (C6H12O6)

  22. If the pH of seawater drops, what is the typical response?
    All the fish die!
    The increased acidity causes carbon dioxide to be absorbed from the atmosphere, further promoting the drop in pH.
    The increased acidity causes carbonate to dissolved from seafloor sediments, thus limiting the drop in pH.
    The increased acidity causes oxygen to be absorbed from the atmosphere, thus limiting the drop in pH.
    The increased acidity causes silica to dissolved from seafloor sediments, further promoting the drop in pH.

  23. What is a good way to get calcium carbonate to precipitate out of seawater?
    Add acid to the water
    Add oxygen to the water
    Raise the pressure
    Raise the salinity
    Raise the temperature

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