1. ACIDS AND BASES

2. What is an Acid?
An acid is a substance that, when dissolved in water, produces positive hydrogen ions (H+).
The more H + ions, the more acidic the solution.

3. Properties of Acids
1. Acids have a sour taste.

4. Properties of Acids
2. Acids are corrosive – having the ability to “eat away” at metals like iron, zinc, and magnesium. - Hydrogen gas is produced.

5. Properties of Acids Example: calcium carbonate (CaCO3) or limestone
3. Acids react with carbonates to produce carbon dioxide.
- Carbonates are ions containing carbon and oxygen atoms bonded together.
Example: calcium carbonate (CaCO3) or limestone

6. Properties of Acids
4. Acids turn blue litmus paper red.

7. Some Uses of Acids Acetic Acid (C2H4O2) – Vinegar
Ascorbic Acid (C6H8O6) –
Vitamin C
Citric Acid (C6H8O7) – found in lemons, limes, oranges, and sour candies

8. Some Uses of Acids
Hydrochloric Acid (HCl) – used in the production of plastics, household cleaning products, and food additives
Sulfuric Acid (H2SO4) - used in the production of fertilizers, paints, and plastics

9. What is a Base?
A base is a substance that, when dissolved in water, produces negative hydroxide ions (OH-).

10. Properties of Bases
1. Bases have a bitter taste.

11. Properties of Bases
2. Bases have a slippery feel.

12. Properties of Bases
3. Bases turn red litmus paper blue.

13. Some Uses of Bases
Ammonia (NH3) – used to manufacture dyes, explosives, plastics, and household cleaning products
Calcium Hydroxide Ca(OH)2 – used to make mortar or plaster
Sodium Hydroxide (NaOH) – used to manufacture soap and paper

14. Measuring pH The pH scale is a range of values from 0 to 14.
It expresses the concentration of hydrogen ions in a solution.
A low pH tells you that the concentration of hydrogen ions is high.
A high pH tells you that the concentration of hydrogen ions is low.

15. Measuring pH
A change of 1 pH unit represents a tenfold change in the acidity of the solution.
Example: If one solution has a pH of 1 and a second solution has a pH of 2, the first solution is not twice as acidic as the second—it is ten times more acidic.

16. pH Indicators
A pH indicator is a substance that changes color depending on the pH of the solution with which it is mixed.
- They are often made from plant extracts.

17. Measuring pH with an Indicator

18. Acid-Base Reactions
A reaction between an acid and a base is called neutralization.
An acid-base mixture is not as acidic or as basic as the individual starting solutions.

19. Acid-Base Reactions

20. Acid – Base reactions
Each salt listed in this table can be formed by the reaction between an acid and a base.