Earth Science 11
6.2 Assignment – Composition of Sea Water
Name:___________
1. List the five major oceans recognized by geographers:
a)
d)
b)
e)
c)
2. What is the definition of an OCEAN?
_________________________________________________________________________________
______________________________________________________________________________
_________________________________________________________
3. How much is covered by oceans? __________________
4.
What are two sources of dissolved substances in the ocean?
_________________________________________________________________________________
___________________________________________________________________________
5. What is the average salinity of ocean water? __________
a. List one place where you find low salinity? Why?
______________________________________________________________________________
______________________________________________________
b. List one place where you find high salinity? Why?
______________________________________________________________________________
______________________________________________________
6. What is the main component of ocean water? ____________________
7.
What are the three layers of ocean water? _______________, ___________________,
_____________________
a. Which is the warmest _________________
b. Which has a rapid change in temperature ___________________
8.
What are phytoplankton and why are they important?
______________________________________________________________________________
______________________________________________________________________________
Matty 2014
Earth Science 11
6.2 Assignment – Composition of Sea Water
Name:___________
9. Chemical tests show that the ions of sodium and chlorine (chloride) make up, by far, the largest
percentage of the ocean’s salt content. Only six ions make up more than 99 percent of the total
dissolved load of ocean water. The relative amounts of these ions are shown in the table below.
Each value represents the percentage of all the ions present in ocean water.
Plot the data given in the table in a bar graph. Use the graph and table to answer the questions
below. Chloride has been done for you.
Ion
Chloride (Cl⁻)
Sodium (Na+)
Sulfate (SO42-)
Magnesium (Mg2+)
Calcium (C2+)
Potassium (K+)
All others
Percent (%) of Total Salts
55.0
30.6
7.7
3.7
1.2
1.1
0.7
60
50
40
30
20
10
0
Cl
Na
SO4
Mg
Ca
K
10. What percentage of the dissolved salt load are chloride ions? ____________
11. What are the two most abundant ions in sea water? __________, __________
12. Calculate how many grams of chloride ions are present in 50 grams of ocean salts. Show your
work
_______grams(of ocean salts) X ________(% of Cl as a decimal) = __________grams
13. How many grams of magnesium ions are present in 50 grams of ocean salts? Show work below.
14. How many grams of calcium ions are present in 75 grams of ocean salts? Show work.
Matty 2014
Earth Science 11
6.2 Assignment – Composition of Sea Water
Name:___________
15. Using the following graph, what temperature is seawater below 1500m in the low latitudes?
16. What temperature is seawater at 1000m in the low latitudes.
17. How would you describe the temperature changes in high latitudes. WHY?
18. Circle the letters of the two main factors that influence density of seawater.
a. Salinity
c. Temperature
b. Pycnocline
d. Thermocline
19. Circle the letter of the ocean layer where there is a rapid change of density with depth.
Matty 2014
a. Surface zone
c. Thermocline
b. Pycnocline
d. Transition zone