I. Water Molecule What is a polar molecule? How does the polarity of water affect this molecule?

II. Properties of Water What are the five characteristics of water that emerge due to this hydrogen bonding?

A. Water is Cohesive Cohesion Adhesion Why is it that a person who jumps off a bridge into water, dies?

B. Water Has a High Specific Heat What is specific heat? Why is the specific heat of water high?

C. Water has a High Heat of Vaporization What does this mean? What does this property of water do? Moderates the Earth’s climate Stabilizes the temperature of aquatic ecosystems, which affects the life that lives there. Allows for evaporative cooling

D. Water Expands When It Freezes Explain this discrepancy!

Why ice really does float:

Important factors that result from water’s expansion as it freezes: Prevents deep bodies of water from freezing from the bottom up. As water freezes it releases heat to water below and insulates it. As water freezes H bonds form releasing heat.As ice melts H bonds break absorbing heat. Both of these factors make seasonal transitions less abrupt!

E. Water is a Versatile Solvent Polar compounds dissolve in water. Nonpolar compounds do not dissolve in water.

III. Acids Bases and pH Water molecules dissociate into H+ and OH- At equilibrium the [H+ ] = [OH-] The molar concentrations of these ions = 10-7, which represents a neutral solution pH of a solution = -log [H+ ] [H+] = 10-pH

Acids Bases Reduce the relative [H+ ] of a solution Increase the relative [H+ ] of a solution [H+ ] > [OH-] in an acidic solution Remove [OH-] from a solution which increases the relative [H+ ] For example the acid HCl in a solution converts to [H+ ] + Cl- pH of acidic solution<7 Bases Reduce the relative [H+ ] of a solution [H+ ] < [OH-] in a basic solution Bases either reduce [H+ ] directly…….. NH3 + H+ --> NH4 or indirectly ……... NaOH --> Na+ + OH- pH of basic solution > 7

How much greater is the [H+ ] in a solution with a pH of 2 than a solution with a pH of 6? 10,000