1. HONOURS EXTRA 2: Acids and Bases
Science 9H
HONOURS EXTRA 2:
Acids and Bases

2. Objectives By the end of the lesson you should be able to:
Describe the similarities and differences between acids and bases
Describe how to test for acids and bases

3. Types of Solutions There are 2 types of solutions:
ACIDS (formula starts with H)
BASES (formula ends with OH)

4. Acids Chemicals dissolved in water Cause indicators to change colour
EX: vinegar, apples, coffee, milk, aspirin, stomach acid, lemon juice, HCl, H2SO4

5. Common acid formulas and names
HCl
HNO3
H2SO4
HNO2
HClO4
H2CO3
HBr
H2CrO4
Hydrochloric acid
Nitric acid
Sulphuric acid
Nitrous acid
Perchloric Acid
Carbonic acid
Hydrobromic acid
Chromic Acid

6. Bases Chemicals dissolved in water Causes indicators to change colour
EX: soap, blood, eggs, baking soda, ammonia cleaner, Drano, Windex, TUMS, NaOH, LiOH

7. Indicators Dyes used to classify acids and bases
They do this because they can change to different colours when they come into contact with acids and bases
We use: - Litmus Paper (Red and Blue)
- Bromothymol Blue
- Phenolphthalein
- Methyl Red and Methyl Orange
- Indigo Carmine
- Universal Indicator (U.I.)

8. pH Scale (Colours based on U.I.)1 2 3 4 5 6 7 8 9 10 11 12 13 14
Very Slightly
acidic acidic
Slightly Very
basic basic
Neutral

9. Think about it?
What happens if you mix a strong acid and a strong base?
They will cancel each other out and end up as neutral
BUT: what’s happened to all the chemicals??

10. Neutralizations
Any time an acid and a base react a neutralization has occurred
When mixed together they make a SALT and WATER
acid + base  salt + water
HX + YOH  YX + HOH or (H20)

11. Salts Always dissolve in water
Have a crystal structure when not in water
Have no effect on indicators
Common example: Any ionic compound!!!
NaCl, MgCl2, KBr,