Name___________________________
Ocean Water Chemistry 4-3
Review and Reinforce
Understanding the Main Ideas
Fill in the spaces in the table below
Depth Zone
The Water Column
Depth Range
Surface
o
Average Temperature ( C)
1.
2.
3.
4.
10 C to – 4 C
5.
1 km to ocean floor
6.
o
o
Answer the following questions.
7. What is the average salinity of ocean water?
8. Name three factors that affect how salty the ocean is:
9. Which is more dense, ocean water or fresh water?
10. What is the most abundant salt in sea water?
11. Why is there more oxygen at the surface of the ocean than in deeper
layers?
12. What prevents scuba divers from going deeper than 40 meters below the
surface?
Building Vocabulary
Fill in the space to complete each sentence
13. A _______________________ is an underwater vehicle built of strong materials to resist pressure.
14. The total amount of dissolved salts in ocean water is called________________________.
15. A vertical section of the ocean from the surface to the ocean floor is referred to as the________________
____________________________.
Characteristics of Ocean Water
1. On lines A-D above, write the percentages of elements found in ocean water: 1.1%,
0.5%, 96.5%, and 1.9%
2. On lines E-H above, write the percentages per 1000 of common salts found in ocean
water: 77.75%, 3.60%, 10.89%, and 4.73%.
3. Write the word or words that will make each sentence a true statement.
a. The two most abundant elements in the form of dissolved gases found in ocean water
are:_______________________ and ________________________.
b. When sodium and chlorine unite they form ______________________ commonly called
_______________.
c. The average salinity of ocean water is _____________ parts per ______________________.
d. Three sulfurous salt compounds found in ocean water are _________________________,
_________________________, and ________________________________.
4. Write the word or phrase from Column B in the space before its description in Column A.
Column A
Column B
____________________________
a. affects surface salinity of ocean water
salinity
____________________________
b. amount of dissolved salts in ocean water
bromine
____________________________
c. above average salt content
evaporation & rain
____________________________
d. element extracted from ocean water
tropical ocean water
____________________________
e. used by marine animals in shells
calcium carbonate
5. Why is ocean water salinity greatly reduced at the mouths of the Amazon, Congo and Mississippi rivers?
The Composition of Ocean Water
4-3
Enrich
On average, one kilogram of ocean water contains about 35 grams of salts. That is, salts make up about
3.5% of ocean water. Though sodium chloride is the most abundant and familiar salt in seawater, a variety of
other salts are also dissolved in seawater. The table below lists the salts that a scientist recovered by
evaporating a 100-gram sample of ocean water. The second column lists the mass of each salt recovered.
Major Salts from a Sample of Ocean Water
Mass
Salts
(g of salt recovered from
100 g of ocean water)
Sodium Chloride
2.72
Magnesium Chloride
0.38
Magnesium Sulfate
0.17
Calcium sulfate
0.13
Potassium sulfate
0.08
Calcium carbonate
0.01
Magnesium bromine
0.01
Percentage of Total
Salts
Number of Degrees on
Circle Graph
Follow these steps to complete the table and make a circle graph.
1. Use this equation to fill in the “Percentage of Total Salts” column
Mass of salt
Total salt (3.5g)
2. Multiple the percentage calculated in step 1 by 360 to determine the number of degrees
needed.
3. Draw one line from the center of the circle to the edge.
4. Use a protractor and the number of degrees calculations to complete the pie graph.