Study Questions: Water Properties

1) Water is an excellent dissolver because of the water molecule�s structure.� It is the hydrogen bonds that enable it to be ___________, able to electrostatically attach to ions.

2) What is the definition of a solution? What are solute and solvent?

3) Is pure water a solution?� Is seawater a solution?

4) Define the terms �atom�, �nucleus�, �proton�, �neutron�, �electron�, �ion�, �anion�, and �cation�.

5) What does the Z number or atomic number tell us?� How do we determine the atomic number?

6) The H₂O molecule is composed of two hydrogen atoms and one oxygen atom that are held together by covalent bonds.� What are covalent bonds and why is the water molecule polar (think about the geometry of the molecule)?

7) Seawater is about _________% H2O and about __________% dissolved solids (salts).

8) What is the definition of salinity?

9) What is the average salinity of seawater? ___________� It is best described in units of %, �, ppm, or ppb?

10) Are there any salts in the ocean?

11) What makes up the Salinity of the ocean?

12) How are these ions in solution electrostatically balanced?

13) What are Water�s Four Colligative Properties discussed in lecture? What does salinity do to heat capacity, freezing point, evaporation rates, and osmotic pressures?

14) What is hypotonic, hypertonic, and isotonic? A freshwater fish put into ocean saltwater would become ___________.�� A marine saltwater fish put in a fresh water pond would become _____________.

15) Ocean salinity refers to many dissolved ions in water, not just Na and Cl ions.� Name at least six others.� These charged ions are neutralized by ___________ in seawater?

16) What are trace elements? Do we use parts per thousand for these units?� If not, what units do we use?

17) What are excess volatiles? In other words, other than dissolving rocks, what is another source of the ocean�s ions?

18) What is the Principle of Constant Proportions, Chlorinity?

19) How is seawater salinity routinely measured today (two ways)?

20) In the ocean, what is chemical equilibrium?

21) What is the general concept of a Steady State Ocean?

22) Calculate the residence time of Sulfate Ion, SO₄^-2 if the amount of sulfate in the ocean is 3.63 x 10⁸ grams and the steady state rate of sulfate is 32.99 grams/year.

23) Define �acid�, �base�, �pH scale�, �acidic�, and �alkaline�.

24) Seawater is an excellent buffer solution because it prevents excess swings in pH.� How is this buffering property of seawater related to CO₂.

25) The most important properties of water deal with the absorption and loss of ______.

26) What is the definition of heat and temperature?

27) What is the definition of heat capacity?� Heat capacity is measured in _____________.

28) What is a calorie?

29) What has higher heat capacity, water or granitic sand?

30) What happens to the density of water as it approaches freezing?� How is this expansion accomplished?

31) Why does ice float in water?

32) What is the latent heat of fusion?� What is the latent heat of vaporization?

33) How many heat calories per gram are lost when water freezes during the latent heat of fusion?

34) How many heat calories per gram are absorbed into evaporating water during latent heat of vaporization?

35) Why does it take more heat energy to evaporate water than to make solid ice?

36) Recall that seawater density increases with increasing salinity, increasing pressure, and decreasing temperature.� Thus cold water must be denser (heavier) than warm water.� This causes the ocean to have stratification.� What is stratification?

37) What three fundamental layers can ocean stratification be separated into (see Fig. 6.9 page 106)?

38) The surface and middle layer boundary is defined as rapid changes in either salinity or temperature.� The change in salinity is known as the _____________, and the change in temperature is known as the _____________?

39) The middle layer is also known as the ______________ because both salinity and temperature changes cause rapid changes in density.

40) Light is measured in terms of wavelengths.� What wavelengths of light reach deeper waters (Fig. 6.12, p.107-109)?

41) What is the electromagnetic spectrum?� Know the approximate range for visible light (see Fig. 6.12, page 109).

42) Is sound in the ocean faster or slower than sound in the air?

43) Sound velocities in the ocean are slower or faster than sound velocities in the air?� Know how sound velocity in the ocean varies with temperature, pressure, and density (see pages 109-111).

44) What is the SOFAR Channel (see Fig. 6.14, p. 111)?

45) What is the ATOC experiment.� What is the premise behind the ATOC experiment (check out this link http://atoc.ucsd.edu/)?

46) Discuss sonar, side-scan sonar, multibeam systems, and echo sounder.� What is passive sonar? What organisms in the ocean also use sonar? (see page 118)

47) What is refraction (see pages 108)?