1. Two Types Of Chemical Reactions
Chapter 21

2. Acids Donate and Bases Accept
Acid is any chemical that donates an H+.
A base is any chemical that accepts an H+.

3. Acids Donate and Bases Accept
H3O + - Hydronium ion (Acid)
OH– -Hydroxide ion ( Base)

4. Salt is the Product of an Acid-Base Reaction
Salt and water is the product of an acid- base reaction.
Acid + Base  Salt + water
The reaction between an acid and a base is called a neutralization reaction.

5. Neutralization Reaction

6. Some Acids and Bases Are Stronger Than Others.
Strong acids and bases tend to generate more ions than weak acids or bases.

7. Acid, Base, or Neutral Neutral - Same amount of H+ and OH-
Acid- More H+ than OH-
Base- More OH- than H+

8. pH Scale
The pH scale is used to describe the strength of an acid or a base.
Over 7 is a base, under 7 is an acid, exactly 7 is neutral

9. Formula for pH
pH = - log [H+]

10. Indicators – Acid or Base?
Indicators will determine whether a solution is acidic or basic by changing a certain color.
Indicator
Acid
Base
Litmus paper
Red
Blue
Phenolphthalein
Clear
Pink
Cabbage juice
red
Green-yellow

11. Measuring the pH
To measure the pH of a solution other tools must be used.
pH meter- an electronic device to measure pH.

12. Measuring the pH
Hydrion Paper- paper that turns a different color for every pH.

13. Rainwater is Acidic Rainwater is naturally acidic.
Water in the atmosphere reacts with pollutants to produce acid.

14. Ocean water is Basic Oceans are naturally basic.
The oceans contain bases which neutralize the acids immediately.

15. Effects on the Environment
As human create more pollutants the environment is getting more acidic. This is dangerous to life on land as well as in the oceans.

16. Carbon Dioxide Levels by Year

17. Oxidation and Reduction
Reaction
Electron
Oxidation
Loss of electron
Reduction
Gain of electron

18. The Energy of Flowing Electrons
Electrochemistry- is the study of the relationship between electrical energy and chemical change.
Oxidation and Reduction reactions produce electric current.

19. Electrical Energy
Chemical energy is transformed into electrical energy.

20. Batteries
Batteries create electrical energy by Oxidation-Reduction reactions.

21. Oxygen is Responsible for Corrosion
Corrosion is the process whereby metal rusts.
Iron + Oxygen + Water  Rust

22. Oxygen is Responsible for Combustion
Combustion is an oxidation- reduction reaction between an nonmetallic material and oxygen.
Gas + oxygen  Carbon dioxide + water

23. Oxygen is Responsible for Combustion