1. Aim: To prepare natural indicator papers from hibiscus, rose, turmeric, and red cabbage, and to observe how they react with different substances to determine if they are acidic or basic.
2. Requirements
- Materials: hibiscus flowers, rose petals, turmeric powder, red cabbage leaves, filter paper, water, and a heat source.
- Substances for Testing: lime juice, lime water (calcium hydroxide), baking soda solution.
3. Procedure
I. Prepare indicator papers:
- Rub red hibiscus petals onto white filter paper to create hibiscus indicator paper.
- Rub rose petals onto filter paper and cut into strips to make rose indicator paper.
- Mix turmeric powder with a little water and dip filter paper into it. Let it dry and cut it into strips to make turmeric indicator paper.
- Boil red cabbage leaves in water. Once cooled, dip filter paper in the cabbage solution and dry. Cut into strips to prepare red cabbage indicator paper.
II. Testing substances:
- Put a few drops of each substance (lime juice, lime water, and baking soda solution) onto the prepared indicator papers.
- Observe the colour changes and record the results.
4. Observation Table
| Sr. No. | Substance | Effect on Turmeric Paper | Acidic / Basic |
|---|---|---|---|
| 1 | Lime juice | No change | Acidic |
| 2 | Lime water (calcium hydroxide) | Turns red | Basic |
| 3 | Baking soda solution | Turns red | Basic |
5. Conclusion: Natural indicator papers can be easily made from flowers and plants to test for acidity or basicity. Turmeric paper turns red in the presence of a base, but there is no change when exposed to an acid. This experiment shows how natural indicators can help identify whether a substance is acidic or basic in a simple and safe way.
