What it shows
Red cabbage juice changes colour with acids and bases: pink or red in acids, purple when neutral, and blue, green or yellow in bases.
This idea has a short entry only. For the science behind it, read the sentence above with your textbook and ask your teacher to explain the law or idea it shows, so you can describe it in your own words.
Materials
- Red cabbage leaves and hot water
- A strainer and clear cups
- Lemon juice, vinegar, baking soda solution, soap water and tap water
Safety
For this project: An adult should handle the hot water. Do not taste anything, and do not test bleach or toilet cleaners.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesHow to go about it
Numbered steps have not been written for this idea yet. Plan it with your teacher: sketch the design with measurements, build one part at a time, test each part, and write every observation with the date. The free ebooks below have step-by-step projects of the same kind.
Take it further
Soak filter paper in the juice and dry it to make your own indicator paper.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
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