The Properties of Water Which Are Essential to the Maintenance of Life

The Properties of Water

Which Are Essential to the Maintenance of Life

I. Properties of water are dependent on hydrogen bonding

II. Properties of water

• A. Cohesion– 1. Definition– 2. Example

II. Properties of Water

• B. Adhesion– 1. definition– 2. example of old car hood

II. Properties of Water

• C. Surface tension– 1. Definition– 2. Example

Water strider on pond surface

D. Capillarity

• 1. Definition• 2. Example• 3. Importance

E. Specific heat

• 1. definition

• 2. specific heat of water is 1cal/gram/oC

• 3. specific heat of alcohol is .6cal/gram/oC

• 4. specific heat of water is 10X water

• 5. analogy of kids in mall

F. Heat of vaporization

• Definition

• Water has a heat of vaporization of 580 cal/gram

• Alcohol heat of vaporization is 290 cal/gram

G. Density changes with temperature• Definition of density

G. Density changes with temperature• Graph of density

changes

H. Water as a solvent of ionic molecules causes dissociation

H. Water also dissolves molecules which are hydrophilic almost irregardless of size

I. Water dissociates a little bit – very small percentage

1. At neutral pH the H2O H+ + OH-

• The concentration of hydrogen and hydroxyl ion are equal.

• The product of the two when multiplied together is always equal to 10-14

2. Acid

– a. definition– b. examples– c. what happens to relative concentration

of hydrogen and hydroxyl ion

3. Base

• a. definition

• b. examples

• c. what happens to hydrogen and hydroxyl ion concentrations

4. pH scale