1. Chapter 2

2. Everyday Acids

3. Properties of Acids Dissolves (Stomach acid) Erodes (Acid Rain)
Burns (Battery acid)
Tastes sour

4. Acids
An acid is a compound that releases Hydrogen ions (H+) into solution.
HCL  H+ + CL-
Hydrochloric acid  Hydrogen Ion + Chloride Ion
A strong acid has a lot of H+ ions.

5. Everyday Bases

6. Properties of Bases
Tastes Bitter
Burns
Feels Soapy or slippery

7. Bases
A base is a compound that release hydroxide (OH-) ions into solution.
NaOH  Na+ + OH-
Sodium hydroxide  Sodium Ion + Hydroxide ion.
A strong base has a lot of OH- ions.

8. Why are Acids and Bases important in Biology?
Certain Biological reactions can only occur in acids and bases.
Stomach acid dissolves food
Some digestion in the small intestine requires a base.
Acids and bases can also have an environmental impact.
Dumping of chemicals into rivers, lakes and oceans.
Acid rain.

9. The pH Scale
Acid strength is measured by the concentration of H+ ions. This concentration is called the pH.

11. Enzymes - A Type of Protein
Enzymes function at an optimal pH.
Human enzymes work best at a pH between 6 and 8.
Changing the pH can alter the rate of reaction for an enzyme.

12. Neutralization
Neutralization reaction - When a strong acid and a strong base are mixed together.
H+ + OH-  H2O
A neutral substance has equal amounts of H+ and OH- when dissolved.
A neutral substance has a Ph of 7.
Distilled water.

13. Why are neutralization reactions important in Biology?
Human Blood and cells must maintain a pH of around 7.
Neutralization reactions help maintain a constant pH.
Food going from the stomach to the small intestine has a very high pH. The acid is neutralized before entering the small intestine.

14. Clicker Question The pH scale Measures the strength of an acid
Ranges from 0 to 14
Measures the concentration of H+ ions.
All of the above are correct
None of the above are correct

15. Clicker Question A strong acid Has a high concentration of H+ ions.
Has a low concentration of H+ ions.
Has a high concentration of OH- ions.
Has a low concentration of OH- ions.

16. Clicker Question A strong base Has a high concentration of H+ ions.
Has a low concentration of H+ ions.
Has a high concentration of OH- ions.
Has a low concentration of OH- ions.

17. Clicker Question A substance with a pH of 3 is considered An Acid
A Base
Neutral

18. Clicker Question A substance with a pH of 7 is considered An Acid
A Base
Neutral

19. Clicker Question A substance with a pH of 10 is considered An Acid
A Base
Neutral

20. Clicker Question
The arrow is pointing to an area on the pH scale where A. B. C.

21. Clicker Question Which substance is the strongest base?
Hydrochloric acid
Sodium hydroxide
Rain water
Sea water
Pure water

22. Clicker Question Which substance is the strongest acid?
Hydrochloric acid
Sodium hydroxide
Rain water
Sea water
Pure water

23. Clicker Question Which substance has the highest H+ ion concentration?
Sulfuric acid
Tomatoes
Rain water
Sea Water
Ammonium chloride

24. Clicker Question
Which substance has the highest OH- ion concentration?
Sulfuric acid
Tomatoes
Rain water
Sea Water
Ammonium chloride