Dilution

Aim:
To make a dilution series to investigate concentration.

Equipment:

1. A potassium permanganate crystal.
2. Six test tubes.
3. A plastic transfer pipette.
4. A test tube rack
5. 10mL measuring cylinder.

Method:

1. Place the six test tubes in a test tube rack.
2. Using the measuring cylinder, fill test tube 1 with 10 mL of water. Fill the remaining test tubes with 5mL of water.
3. Add a spatula of potassium permanganate to the first (10mL) test tube of water.
4. Take 1mL from the first tube and add it to the next tube.
5. Take 1mL from the second test tube and add it to the next tube.
6. Take 1mL from the third test tube and add it to the next tube.
7. Take 1mL from the fourth test tube and add it to the next tube.
8. Take 1mL from the fifth test tube and add it to the last tube.

Discussion:

The first test tube was the darkest and carried on through to the sixth test tube getting lighter and lighter.