Aim: To make acid-base indicators using everyday substances.
Equipment:
- Red cabbage
- Large beaker
- Small beaker
- Cloth
- Water
- Glass stirring rod
- Element
- Heatproof mat
- 5 Test tubes
- Test tube rack
- 3ml Pipette
- Hydrochloric acid (HCl)
- Sodium Hydroxide (NaOH)
Method:
- Chop the cabbage into small pieces until you have enough to fill half a beaker.
- Place the chopped cabbage in a large beaker and add water to cover the cabbage.
- Boil over an element until the water starts boiling and bubbling.
- When the water starts bubbling a lot, turn off the element and leave the large beaker to cool on top of the element.
- Once the beaker has stopped bubbling, using a cloth, place the large beaker on the heatproof mat from the element.
- Using a glass stirring rod, tip the liquid into the small beaker leaving the red cabbage in the big beaker.
- Put 5ml drops of hydrochloric acid into one test tube and 5ml of sodium hydroxide to the other test tube.
- Using a pipette, place 5ml of the cabbage indicator into two test tubes.
- Record and observe the colour change.
