Acids, bases and salts · Grade 9
Red-cabbage rainbow
ChemAI · Worksheet
NameClassDate
Aim
A natural indicator shows a different colour at every pH.
Before you start: what do you predict will happen? Why?
What you do
| Step | What I observed | |
|---|---|---|
| 1 | Add acid to one tube. | |
| 2 | Add a base to another tube. | |
| 3 | Make a third colour with sodium carbonate. | |
| 4 | Turn on the pH meter and order the tubes from acidic to basic. |
Questions
- Write a word or symbol equation for one reaction you observed.
- Explain your most important observation using particles, ions or energy.
- Was your prediction right? What would you change to get a more reliable result?