ESH Properties of Sea Water (I)
Name:______________________________________________________Period: ________
Data Table 1: Conductivity of Seawater
Salt
Sodium chloride (NaCl)
Magnesium chloride (MgCl2)
Sodium sulfate (Na2SO4)
Calcium chloride (CaCl2)
Potassium chloride (KCl)
Sodium bicarbonate
(NaHCO3)
Potassium bromide (KBr)
Mass (grams)
2.348
.498
.392
.110
.066
.019
Percent (%)
2.348
ppt (o/oo)
23.48
ppm
23, 480
.010
Data Table 2: Conductivity of Seawater
Conductivity of Seawater (yes or no)
Conductivity of Freshwater (yes or no)
Data Table 3: Dissolved Oxygen and pH
Sample
Distilled Water
Tap Water
Sea Water
Salinity (o/oo)
Amount of Dissolved
Oxygen
pH
0
0.1
35
Data Table 4: Chlorine, Alkalinity and pH of Sea Water
Test
Chlorine (ppm)
Alkalinity (ppm)
pH
Amount in Sea water
1|ESCP
Analysis Questions:
***Use your textbook and the introduction to this lab to answer the following questions thoroughly and
completely.
1. You are going to use Excel to generate a graphic model (pie chart) of the percentage of total mass of
dissolved salts. You used a total mass of 3.443 grams of salts to make your salt water. Label each salt in
the key by analyzing the amounts of relative salt you added when making your salt water.
2. What are the six most abundant components (elements) dissolved in seawater? What is produced
when the two most abundant elements are combined? (text-13)
3. What are the twp primary sources for the materials that comprise the dissolved components of
seawater? (text-13)
4. Identify three resources obtained from salt water and their uses as discussed in class.
5. Identify the salts (used in this lab to make your seawater) from which each of the three resources
mentioned in question 4 were obtained.
6. Which type of water conducted electricity? Explain why it did so.
7. Which type of water did not conduct electricity? Explain why it did not.
8. Which of you samples tested contained the most dissolved oxygen?
9. Most aquariums have “bubblers” (aerator) in them to produce bubbles and add oxygen to the water.
Explain why these are important to an aquatic ecosystem.
10. In addition to a bubbler (aerator), how else could dissolved oxygen be added to a fish tank?
11. Define pH. Would you describe the pH of your sea water as acidic, neutral, or basic?
12. Did you observe a relationship between the pH and amount of dissolved oxygen? Explain.
13. What property of water “directly determines the solubility (amount that can be dissolved in the water)
and biological availability (amount that can be utilized by aquatic life) of chemical constituents such as
nutrients (phosphorus, nitrogen, and carbon) and heavy metals (lead, copper, cadmium, etc.)?”
Explain.
14. Compare the pH of your sea water obtained using the pHydrion strip to the pH obtained using the
Insta-TEST strip. If there was a difference, conjecture why this may have occurred.
15. Distinguish among the three basic types of seafloor sediment, and give an example of each. (text-12)
16. What is the most common type of biogenous sediment? What is the chemical formula for this
sediment? What two salts used in this lab to make your sea water would have contributed ions to help
generate this sediment? (text-12)
17. Define alkalinity. Describe your seawater’s alkalinity. How would your seawater’s alkalinity affect any
organisms that lived in it?
18. Using Excel, generate the following line graphs:
a. Salinity (x-axis) vs. dissolved oxygen (y-axis)
b. pH (x-axis) vs. dissolved oxygen (y-axis)
19. Analyze your graphs (generated in question 18). Describe the relationships between your variables for
each graph.
a. Relationship between salinity and dissolved oxygen
b. Relationship between pH and dissolved oxygen
2|ESCP