Activity 2.4 Let us find out Table 2.3 Testing the nature of samples Class 7
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Activity 2.4 Let us find out Table 2.3 Class 7
Activity 2.4 Let us find out (Pages 12-13) Table 2.3 Class 7
Answer:
Table 2.4 Testing the nature of samples with turmeric paper
| S.No | Name of the sample | The colour of the red rose extract after adding the sample | Nature of the substance |
| 1. | Lemon juice | Red | Acidic |
| 2. | Soap solution | Green | Basic |
| 3. | Amla juice | Red | Acidic |
| 4. | Baking soda solution | Green | Basic |
| 5. | Vinegar | Red | Acidic |
Observation and conclusion:
Turmeric paper changes the colour of basic solution from yellow to red but does not change the colour in acidic or neutral solutions.
Question 1.
Are there any substances whose odours change on adding acidic or basic substances? What are these substances called?
Answer:
Yes. There are substances like onion, clove oil and vanilla extract whose odours change when added to acidic or basic substances. These substances are called olfactory indicators.