1. Define and relate the following: solute, solvent and solution. What does solubility measure? 

2. What is an ion? What holds ionic compounds together? What happens when they dissolve?

3. What does it mean when we say “water is a polar molecule”? How does this make it an effective solvent?

4. Use this graph to describe the general relationship between salt solubility and temperature. How does solubility relate to saturation and precipitation?

5. Define and relate the following: ions and salinity.  What is the average salinity of seawater (make sure to include appropriate units). Copy and paste Fig. 7.4 into your response. Use this figure to describe the main ions dissolved in seawater. 

6. What are the two main sources of salt to the ocean?

7. There are three main gases dissolved in ocean water: nitrogen (N₂), Oxygen (O₂) and carbon dioxide (CO₂). Choose ONE of these. Discuss its sources to the ocean and its importance to the ocean environment. (Up to THREE students may respond to this question without penalty, provided that different each student responds with a different gas)

8. Up to THREE students may reply to this question without penalty, provided each choose a different letter to respond to:

a. Copy and paste Fig. 5.4.1 into your response. Use this figure to describe how the concentration of oxygen changes with depth. 

b.  Copy and paste Fig. 5.5.1 into your response. Use this figure to describe how the concentration of carbon dioxide changes with depth. 

c. Use what you know about the biological importance of oxygen and carbon dioxide to explain why gas concentrations change this way with depth.

9. Copy and paste Fig. 5.3.2 into your response. Explain what this graph shows and hypothesize about why those patterns appear. 

10. What does pH measure? What is the average pH of the ocean? 

11. Describe the system of chemical equations responsible for preventing broad swings in pH?

12. Copy and paste Fig. 5.5.6 into your response. Use this figure to explain how the bicarbonate ion (HCO₃^–) plays a role in the carbonate buffer system to help maintain constant pH in the ocean.

13. How do temperature and pressure change with depth in the ocean? How does gas solubility vary with temperature and pressure (Hint: It may help to revisit the graph from our Learning Discussion Board – Graphical Analysis: Gas Solubility)?

14. Define the calcite compensation depth (CCD) and relate to how CO₂ concentration changes with depth.

15. Why is the CCD deeper in the Atlantic Ocean compared with the Pacific or Indian Oceans?

16. Copy and paste Fig. 5.5.3 into your response. Describe what this figure shows. Define and relate the carbonate buffer system to the causes of ocean acidification.

17. Copy and paste Fig. 5.5.3 into your response. Describe what this figure shows. Define and relate the carbonate buffer system to the consequences of ocean acidification.

18. Define and relate ions with colligative properties. Describe ONE of the four ways that dissolved ions affect the properties of water? (Up to FOUR students may respond to this question without penalty, provided that different colligative properties are described).