1. Litmus Indicator Learning objective Examples of acids and alkalis
Describe how to use litmus indicator
Identify acids and alkalis using litmus indicator

2. What do all these things have in common?

3. What is an indicator?
How can you test a liquid to find if it is an acid or an alkali?
An indicator is a special chemical that changes
to a different colour in an acid or an alkali.
Litmus paper and litmus solution are examples of indicators.
Red Litmus is red in acid. Blue litmus turns red in acid
Blue Litmus is blue in alkali. Red litmus turn blue in alkali

4. Litmus test experiment
The results for the litmus tests are:
Tube 1. The solution is an alkali which turns blue when red litmus is added to it and remains blue when blue litmus is added to it.
Tube 2. The solution is an acid which remains red when red litmus is added to it and turns blue when red litmus is added to it.
Tube 3. The solution is water which remains red when red litmus is added to it and remains blue when blue litmus is added to it.

5. The Litmus Test Wear goggles! Aim:
Use Litmus Paper to identify different acid, alkali and neutral solutions.
Wear goggles!

6. Method: Collect your equipment.
In 9 wells of a spotting tile add one piece of red litmus paper.
To each well add 2 drops of each substance following the grid below.
kettle descaler
tap water
battery acid
oven cleaner
kitchen surface cleaner
ammonia
shower cleaner
bleach
Vinegar
Record the colour that the red litmus paper has changed to in your results table.
Using a paper towel put the litmus paper in the bin. Rinse and dry the spotting tile.
Repeat steps above using blue litmus paper.
Identify the solution as acid, alkali or neutral.

7. Kitchen surface cleaner
Kettle descaler
Tap water
Battery Acid
Oven cleaner
Kitchen surface cleaner
Ammonia
Shower cleaner
Bleach
Vinegar

8. Kitchen surface cleaner
Household cleaners
Red litmus
Blue Litmus
Acid or alkali?
Kettle Descaler
Oven cleaner
Shower cleaner
Tap water
Kitchen surface cleaner
Bleach
Battery Acid
Ammonia
Vinegar

9. Kitchen surface cleaner
Household cleaners
Red litmus
Blue Litmus
Acid or alkali?
Kettle Descaler
Acid
Oven cleaner
Alkali
Shower cleaner
Tap water
Neutral
Kitchen surface cleaner
Bleach
Battery Acid
Ammonia
Vinegar