Aquatic Science Chemistry of Water

1. Give an example of freezing point depression.

adding salt to roads in winter to melt ice

2. What is the most prevalent gas in the ocean?

Nitrogen

3. What is adhesion?

the ability of different molecules to attract one another, causing one substance to stick to a different one. Water attracted to other materials.

4. What is cohesion?

the attraction of water molecules to other water molecules.

5. What is the universal solvent?

Water, its polar molecular structure allows it to dissolve a wider variety of substances than any other liquid, including salts, sugars, and some gases.

6. What is the average salinity of the ocean in % form?

3.5%

7. Does salt or fresh water evaporate slower?

Salt water evaporates slower.

8. What is the most prevalent inorganic element in seawater?

chlorine

9. Who conducted the first scientific study of seawater?

Robert Boyle

10. What percent of ocean water is solvent?

96.5%

11. What are the common inorganic elements found in seawater?

chloride (Cl−), sodium (Na+), sulfate (SO24−), magnesium (Mg2+), calcium (Ca2+), and potassium (K+).

12. Where do dissolved solids in the ocean primarily come from?

chemical weathering of rocks land and mineral rich fluid flows from hydrothermal vents on the seafloor.

13. What are the four divisions of the chemical composition of the ocean?

dissolved inorganic matter, dissolved gases, dissolved organic matter, and particulate matter.

14. As you go deeper in the ocean what happens to oxygen? And carbon dioxide?

oxygen levels generally decrease to a minimum before potentially increasing at the deepest levels, while carbon dioxide concentrations generally increase

15. Who determined that water is a compound of hydrogen and oxygen

Lavoisier

16. What happens to the cells of a saltwater fish if placed in freshwater?

absorb excess water through osmosis

17. What quality makes water the universal solvent?

polar molecular structure

18. What discoveries were made by the Dittmar Challenger Expedition?

while the overall salinity of ocean water varies by location, the ratio of the major dissolved ions remains remarkably constant across the world's oceans.

19. In a single water molecule, what kind of bonds connect the oxygen to the hydrogen atoms?

covalent bonds

20. What kind of bond connects two separate water molecules to each other?

hydrogen bonds

21. How much more dense is water than air?

800 times

22. What sources provide oxygen gas to the ocean?

atmospheric dissolution and ocean plants

23. Surface tension of water is due to strong cohesive forces between water molecules, caused by

hydrogen bonding.

24. How many cubic miles of water are in earth's oceans?

over 285 million

25. What is residence time?

the average length of time a water molecule spends in a specific reservoir

26. What happens to pH as you move deeper in the ocean?

the pH generally decreases

27. What allows organisms to skim or stand on water?

water's high surface tension due to cohesion

28. What happens to water when it goes from liquid to solid state?

the hydrogen bonds spread the molecules into a crystal structure.

29. The increase in salinity from the surface to deeper waters is known as the

halocline.

30. In a solution, the substance being dissolved is the

solute.

31. When a raindrop clings to a leaf this is an example of

adhesion.

32. What happens to the boiling point when you add more solutes to a solvent?

the boiling point of the solution increases

33. ___acids/bases__ produce H+ ions in a water solution.

Acids

34. ___acids/bases__ produce OH− ions in a water solution.

Bases

35. What does pH measure?

the acidity or basicity (alkalinity) of an aqueous solution

36. What kind of organisms don’t require oxygen to survive?

anaerobic organisms

37. What is the pH of the ocean?

around 8.0

38. What is osmosis?

Fluids diffuse from areas of high concentration to areas of lower concentration.

39. On the pH scale acids range from

0 to 7 and bases range from 7 to 14.

40. What are the 3 common types of desalination?

Distillation, Reverse Osmosis, and Electrodialysis

41. A surfactant is

[hydrophobic, hydrophilic, both]. (circles one)