1. Lesson: Acids and Bases

2. All acids have a sour taste.
Carbonic acid
Citric acid

3. Some acids are corrosive.
What elements are contained in these acids?
Sulfuric acid.
Hydrochloric acid.
(H2SO4)
(HCl)

4. Which hazard symbol represents corrosive?

5. How would we test for an acid?
Try some experiments.
Use litmus paper.
What did you find out?
Acids turn blue litmus paper ____
red.

6. Bases are the opposite of acids.
Toothpaste
Soap
Cleaning agents

7. Strong bases include: Sodium hydroxide Calcium hydroxide (NaOH)
Ca(OH)2
What elements are contained in these bases?

8. Strong bases include: NON- CORROSIVE
Sodium hydroxide is also called caustic soda because it is corrosive.
Calcium hydroxide is also called limewater.

9. Bases that dissolve in water are called:
Alkalis
So ______ are bases soluble in water.
alkalis

10. How would we test for a base or an alkali?
Try some experiments.
Use litmus paper.
What did you find out?
Alkali turn red litmus paper ____.
blue

11. pH 7 is neutral. It is not an acid or a base.
The strength of acids and bases can be measured on a pH scale.
Each colour represents a number on the pH scale.
Strong acid
Weak acid
Weak base
Strong base 1 3 5 7 9 11 12 14
pH 7 is neutral. It is not an acid or a base.

12. pH 7 is neutral. It is not an acid or a base.
Each colour represents a number on the pH scale.
Strong acid
Weak acid
Weak base
Strong base 1 3 5 7 9 11 12 14
pH 7 is neutral. It is not an acid or a base.
We can measure pH using universal indicator.

13. Each colour represents a number on the pH scale.
Strong acid
Weak acid
Weak base
Strong base 1 3 5 7 9 11 12 14
Now, use universal indicator to find the pH of some substances.

14. 1. What acid is found in your stomach?
Review Questions
1. What acid is found in your stomach?
2. Which pH is neutral? 1 3 5 7 9 11 12 14
3. What would you use to measure pH?

15. Question to think about!
What happens when you add an acid to a base?