1. Solutions and pH
Chapter 2

2. Definitions:
1. Solution = a mixture in which one or more
substances is distributed in another.
2. Solute = the substance dissolved
in the solution
3. Solvent = substance in which the
solute is dissolved

3. **Acids and bases are created due to dissociation. **DISSOCIATION =
Breaking apart of water molecules
H2O = H+ and OH-
Hydrogen Ion
Hydroxide Ion

4. If the number of HYDROGEN IONS is greater than the number of hydroxide ions, the solution is an . . .
Acid
Ion = an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
H+ > OH-

5. If the number of HYDROXIDE IONS is greater than hydrogen ions, the solution is a . . .
Base
OH- > H+

6. Scientist have developed a Scale to compare the concentration of H+ ions to OH- Ions in Solution called the pH SCALE.

7. pH Scale
Scale ranges from 0 to 14
0=more acidic
7=neutral
14= more basic

8. ----------------------------------------------------------------
The strength of an acid or base is measured on the pH scale. The term “pH” is short for “potential of hydrogen.” It is a measure of how many excess H+ ions there are in a solution. The pH scale runs from 0 to 14, with 0 representing the highest concentration of hydrogen ions. Acidic substances have a pH below 7, while alkaline substances (bases) have a pH above 7. Pure water has a pH of 7 and is considered neutral.
Find the pH of several different substances at the lab tables.

9. =Chemical substances that
Buffers
=Chemical substances that
neutralize small
amounts of
either an acid or a base
 EX: human blood contains a buffer called carbonic acid (H2CO3) and bicarbonate anion (HCO3-). These buffers help to maintain blood pH levels so that they stay between 7.35 and 7.45.

10. Buffers

11. Buffers (first 2 mins)