Learning Objectives for Chemistry of Water

Understand and be able to use the following terms:

water	electronegativity	polar molecule	nonpolar molecule
hydrogen bonds	cohesion	adhesion	surface tension
specific heat	heat of vaporization	hydration shell	hydrophobic
hydrophilic	hydrophobic exclusion	ionization	hydroxide ion
mole	molar concentration	ph	ph scale
acids	bases	buffers

1. Diagram and describe how hydrogen bonds form between water molecules, including an explanation of why water is polar, and how this leads to the formation of hydrogen bonds.
2. In a glass of water, what proportion of the water molecules will form hydrogen bonds at any given time. Are these bonds stable or transient? In what way are hydrogen bonds analogous to Velcro?
3. Name, and briefly explain the five properties of water. Give an example of how each benefits life. Explain the role of hydrogen bonds for each property.
4. Define specific heat. How does the specific heat of water compare to that of other molecules? How does specific heat relate to polarity of a molecule?
5. What types of atoms participate in the formation of hydrogen bonds?
6. Distinguish between hydrophilic and hydrophobic. What types of molecules are hydrophilic? What types of molecules are hydrophobic? Why do these two types of molecules behave differently in water?
7. Describe the phenomenon of hydrophobic exclusion.
8. What ions are formed when water dissociates?
9. What is molar concentration of H⁺ in pure water?
10. Describe the pH scale. What does a pH unit represent? Which values are acid? Which values are basic?
11. Distinguish between acids and bases.
12. What is a buffer? Why are buffers important to organisms?