Find the acidic or basic nature of some substances used in daily life.
Materials: Substances to examine red and blue litmus papers, dropper.
Let's do: Place a few red and few blue litmus paper strips on a surface. Put a drop of a solution of substances on each strip and observe the change in colour.
Observation:
Sr. No.
Solution
Effect on blue litmus paper
Effect on red litmus paper
Inference
1
Lemon water
2
Detergent solution
3
Soap solution
4
Table salt solution
5
Hydrochloric acid
6
Sodium hydroxide
7
Shampoo
8
Baking soda solution
9
Lime water
Important Questions on Acids, Bases and Salts
Make a natural indicator using turmeric powder.
Material: Turmeric powder and blotting/filter paper
Let's do:
1. Take 1 tablespoon turmeric powder and make a paste by adding little water to it.
2. Now, dip a blotting paper/filter paper in the paste and dry it.
3. Cut thin strips of this turmeric paper. These strips can now be used as indicators.
4. Using a dropper, put a drop of orange juice and lime water on the turmeric paper. Observe and
record your observation.
Observation:
| S. No | Solution | Effect on turmeric paper | Inference |
| 1 | Orange juice | ||
| 2 | Lime water |
Make a natural indicator from China rose petals.
Materials: China rose petal, boiling water
Let's do: 1. Take some petals of China rose (Gudhal) in a beaker and add boiling water to this.
2. Keep the mixture undisturbed for some time till the water becomes coloured. This coloured water can
now be used as an indicator.
3. Put different solutions with China rose extract indicator. Record your observations.
Observations:
| S.No | Solution | Effect on China rose extract | Inference |
| 1 | Milk | ||
| 2 | Lemon juice | ||
| 3 | Soap solution | ||
| 4 | Tomato juice | ||
| 5 | Tamarind juice |
