OCN 201 Fourth Reading Discussion Questions

Water and Seawater I

Trujillo and Thurman - Chapter 5

1. Read the caption on p. 128 and describe the number of water molecules in a single droplet of water.

2. Explain why a water body, like a lake or the ocean, freezes from the top down.

5.1 Why Does Water Have Such Unusual Chemical Properties?

Atomic Structure

3. List the three fundamental atomic particles, and state which two are in the nucleus. (Also see fig. 5.1)

4. Give the relative charges for a proton, a neutron, and an electron. (Also see fig. 5.1)

5. Explain why most atoms are electrically neutral.

6. Define ion. (Also see p. 525)

The Water Molecule

7. Define molecule. (Also see fig. 5.3 and p. 527)

Geometry

8. Describe a water molecule's shape. (Also see fig. 5.2a)

Polarity

9. Which end of the dipolar water molecule is negative and which is positive? (Also see figs. 5.2, 5.3, and 5.4)

Interconnections Of Molecules

10. Define hydrogen bond. (Also see fig. 5.3 and p. 524)

11. Contrast the strengths of hydrogen bonds between water molecules and the covalent bonds within a water molecule.

12. Explain why water has a high surface tension.

Water: The Universal Solvent

13. Define ionic bonding. (Also see fig. 5.4a and p. 525)

14. Explain how water molecules break ionic bonds, e.g. NaCl. (Also see fig. 5.4)

15. Define hydration. (Also see fig. 5.4b)

16. Explain why water is called the universal solvent.

5.2 What Other Important Properties Does Water Possess?

Water's Thermal Properties

17. List the three states of water on Earth's surface. (Also see fig. 5.5)

18. What is required to break bonds to change the state of matter? (Also see fig. 5.5)

19. Define heat. (Also see p. 523)

20. Define calorie. (Also see p. 518)

21. Define temperature. (Also see p. 533)

22. Use figs. 5.5 and 5.9 to contrast the relative amounts of bonding in ice, water, and water vapor.

Water's Freezing And Boiling Points

23. Give the temperatures at which pure water freezes and boils. (Also see fig. 5.6)

24. Explain why water's condensation and boiling points are high compared to similar substances. (Also see fig. 5.6)

Water's Heat Capacity And Specific Heat

25. Define heat capacity. (Also see p. 524)

26. Give the specific heat capacity of water in calories. (Also see fig. 5.7)

27. Where does most of the energy go when water is heated? (Note: it does not go into kinetic energy)

Water's Latent Heats

28. Give water's latent heat of melting in calories. (Also see fig. 5.8)

29. Define latent heat of melting. (Also see fig. 5.8 and p. 525)

30. Explain where the 80 cal goes and why water's temperture does not increase at the melting point. (Also see fig. 5.8)

31. Define latent heat of vaporization. (Also see fig. 5.8 and p. 525)

32. Give water's latent heat of vaporization in calories. (Also see fig. 5.8)

33. Explain why water's latent heat of vaporization more than 7x greater than its latent heat of melting. (Also see figs. 5.8 and 5.9)

34. Define evaporation. (Also see p. 522)

35. Explain how evaporation cools matter.

36. Give water's latent heat of evaporation at 20^oC.

Global Thermostatic Effects

37. Describe water's global thermostatic effects.