1. Acids and bases

2. Learning goals We are learning to identify acids and bases.
We are learning to use the pH scale to determine the strength of acids and bases.

3. Properties of acids An acid is a compound that: tastes sour
corrodes metals and tissue
conducts electricity when dissolved in water
react with metals
turns blue litmus paper red

4. Properties of bases An base is a compound that: tastes bitter
has a slippery texture
conducts electricity when dissolved in water
corrodes tissue
don‘t react with metals
turns red litmus paper blue

5. Acid-base indicators
a substance that changes colour when added to an acid or a base.
Litmus paper is a type of acid-base indicator that often comes in two colours: red and blue.
Acids turn blue litmus paper red.
Bases turn red litmus paper blue.

6. pH scale
The pH scale is a scale from 0 to 14 that describes how acidic or basic a substance is.
The lower the pH number, the more acidic a substance is.
The higher the pH number, the more basic a substance is.

7. When pH changes by one, the strength of the acid or base changes by ten times.

8. Naming acids
Ionic compounds with a hydrogen as the metal attached to a non-metal
use prefix “hydro”
stem of element
suffix “ic”
word “acid”
HCl: hydrochloric acid

9. Naming bases Usually have an –OH (hydroxide) group attached to a metal
NaOH – sodium hydroxide

10. Learning goals We are learning to identify acids and bases.
We are learning to use the pH scale to determine the strength of acids and bases.