Red Cabbage Indicator

 Aim:

I want to find out how red cabbage can tell if a liquid is an acid or base.

Research:

Method:

Equipment:

• Beaker
• Red Cabbage
• hydrochloric acid (the acid)
• sodium hydroxide ( the base)
• Something to mix with. (we used a dropper)
• Boiling water.
• Test tube. 

Instructions:

1. Get all your equipment
2. Wash your hands.
3. Pour boiling water into a big beaker.
4. Rip the red cabbage into little pieces.
5. Add the bits of red cabbage into the beaker.
6. Mix the red cabbage with the boiling water until it becomes a dark colour. (we used a dropper to mix it together)
7. After mixing, with a dropper, add about 10 drops of the red cabbage juice into each of the big test tubes.
8. Add 10 drops of the acid on one of the test tubes and add 10 of the base to the other test tube.
9. The test tube that has only acid on it and the test tube that only has the base in it are the full colours if you only add acid or base.
10. Experiment with the red cabbage, the acid and the base. Add as many drops to make different colours.

Results:

Discussion: 

What is an acid and a base? 

An acid is a substance that contains a lot of hydrogen ions. Hydrogen ions is when a hydrogen atom loses or gains an electron. A base is a substance that has a lot of hydroxide ions. Hydroxide ions is when oxygen and hydrogen atoms it is held together by one pair of electron. Acid can give protons to base. And base can accept protons given from the acid.

What do chemical indicators do?

Chemical indicators gives a visible sign to represent what substance it has. The visible sign is the liquid changing colours.