©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
EVSC2050 Exam 2 Study Guide.
Law of Constant Proportions - answer✔(dittmar) Regardless of variations in salinity, the ratios
btwn the amounts of major ions in open ocean water are constant. The concept that ions in
ocean water a found in constant proportions
Salinity - answer✔the total amount of dissolved solids in seawater in parts per thousand by
weight, average salinity is 35 ppt
salinometer - answer✔measures salts by measuring electrical conductivity
Conductivity - answer✔Calculate salinity using the these properties of seawater, calibrating the
results against chloride content and correcting for changes in temperature.
Seawater conducts electricity easily because is contains dissolved salts. The higher the salinity,
the greater the conductivity of the water. depends on both salinity and temperature so
salinometer measurements have to be corrected for the temperature of the water.
Chlorinity - answer✔Grams of chloride ions per 1000 grams of seawater.
Chlorinity of seawater - answer✔19.35 g/kg, 19.87 g/l
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Sources of the salts - answer✔originally from the crust and mantle of the Earth, also
increasingly from weathering of rock, oceanic vents
Anion - answer✔an ion with a negative charge (chloride)
Cation - answer✔an ion with a positive charge (sodium)
Major Constituents - answer✔Na and Cl account for 86% of ions in oceans, conservative
constituent, also sulfate
Minor Constituents - answer✔elements other than the major constituents, less than 1 ppm,
nonconservative, ex: iodine
Nutrients - answer✔nitrogen and phosphorous needed for plant/ phytoplankton growth,
silicate for silica (hard outer shell for single celled org. like diatoms)
percentages of gases in atmosphere - answer✔N:78%, O:21%, CO2: .03%
how long ago did oxygen appear in earth's atmosphere - answer✔2BYA
percentages of gases in surface water - answer✔n: 48%, 0: 36%, CO2: 15%
Trace Elements - answer✔less than 1 ppm, same as minor ex. iodine, metals
calcium is removed from seawater to form - answer✔limestone + shells, but replaced by rivers
and hot springs
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, ©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Gelbstoffe - answer✔Yellow Colored dissolved organic matter, CDOM absorbs shorter
wavelength blue to UV light unlike pure water which absorbs red light., highly populated area of
plant and animal life
Oxygen Minimum - answer✔800m
as temp. and salinity increases, saturation concentration: - answer✔increases
as pressure increases, saturation concentration: - answer✔decreases
Dissolved Gases - answer✔Inert gases like nitrogen , Non-conservative gases like oxygen and
carbon dioxide are influenced by sea life. Gases dissolve more readily in cold water, water with
low salinity, and water under pressure. Conversely, warm waters (similar to warm sodas) can
hold less gas. Very saline water has less gas. Deep, cold ocean water commonly contains
relatively higher concentrations of dissolved gases.
euphotic zone - answer✔lighted portion of the ocean, respiration @ all depths
compensation depth - answer✔depth @ which rate of photosynthesis matches rate of
respiration, above this more O2 than CO2, below vice versa
bottom water is - answer✔anoxic- no dissolved oxygen
anaerobic bacteria live here
Oxygen - answer✔is only added to the oceans at the surface, from atmosphere or
photosynthesis,
3|Page
ALL RIGHTS RESERVED.
EVSC2050 Exam 2 Study Guide.
Law of Constant Proportions - answer✔(dittmar) Regardless of variations in salinity, the ratios
btwn the amounts of major ions in open ocean water are constant. The concept that ions in
ocean water a found in constant proportions
Salinity - answer✔the total amount of dissolved solids in seawater in parts per thousand by
weight, average salinity is 35 ppt
salinometer - answer✔measures salts by measuring electrical conductivity
Conductivity - answer✔Calculate salinity using the these properties of seawater, calibrating the
results against chloride content and correcting for changes in temperature.
Seawater conducts electricity easily because is contains dissolved salts. The higher the salinity,
the greater the conductivity of the water. depends on both salinity and temperature so
salinometer measurements have to be corrected for the temperature of the water.
Chlorinity - answer✔Grams of chloride ions per 1000 grams of seawater.
Chlorinity of seawater - answer✔19.35 g/kg, 19.87 g/l
1|Page
, ©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Sources of the salts - answer✔originally from the crust and mantle of the Earth, also
increasingly from weathering of rock, oceanic vents
Anion - answer✔an ion with a negative charge (chloride)
Cation - answer✔an ion with a positive charge (sodium)
Major Constituents - answer✔Na and Cl account for 86% of ions in oceans, conservative
constituent, also sulfate
Minor Constituents - answer✔elements other than the major constituents, less than 1 ppm,
nonconservative, ex: iodine
Nutrients - answer✔nitrogen and phosphorous needed for plant/ phytoplankton growth,
silicate for silica (hard outer shell for single celled org. like diatoms)
percentages of gases in atmosphere - answer✔N:78%, O:21%, CO2: .03%
how long ago did oxygen appear in earth's atmosphere - answer✔2BYA
percentages of gases in surface water - answer✔n: 48%, 0: 36%, CO2: 15%
Trace Elements - answer✔less than 1 ppm, same as minor ex. iodine, metals
calcium is removed from seawater to form - answer✔limestone + shells, but replaced by rivers
and hot springs
2|Page
, ©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Gelbstoffe - answer✔Yellow Colored dissolved organic matter, CDOM absorbs shorter
wavelength blue to UV light unlike pure water which absorbs red light., highly populated area of
plant and animal life
Oxygen Minimum - answer✔800m
as temp. and salinity increases, saturation concentration: - answer✔increases
as pressure increases, saturation concentration: - answer✔decreases
Dissolved Gases - answer✔Inert gases like nitrogen , Non-conservative gases like oxygen and
carbon dioxide are influenced by sea life. Gases dissolve more readily in cold water, water with
low salinity, and water under pressure. Conversely, warm waters (similar to warm sodas) can
hold less gas. Very saline water has less gas. Deep, cold ocean water commonly contains
relatively higher concentrations of dissolved gases.
euphotic zone - answer✔lighted portion of the ocean, respiration @ all depths
compensation depth - answer✔depth @ which rate of photosynthesis matches rate of
respiration, above this more O2 than CO2, below vice versa
bottom water is - answer✔anoxic- no dissolved oxygen
anaerobic bacteria live here
Oxygen - answer✔is only added to the oceans at the surface, from atmosphere or
photosynthesis,
3|Page
