---
title: "NCERT Solutions for Class 7 Science Chapter 2 Exercise 2.6"
url: https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-6
dateModified: 2026-10-07T16:06:22+00:00
---

# NCERT Solutions for Class 7 Science Chapter 2 Exercise 2.6

Chapter 2: Exploring Substances: Acidic, Basic, and Neutral. Every question from Exercise 2.6, with full working and the final answer.

Free PDF (16 pages): https://www.swavid.com/api/seo/pdf/ncert/science/class-7/swavid-ncert-solutions-class-7-science-chapter-2-exploring-substances-acidic-basic-and-neutral-13aedb74b7.pdf

## Activity 2.6: Let us investigate

### Question 1

*Activity*

Check the odour again.

**Solution**

1. Smell the onion strips after adding tamarind water or baking soda solution to observe any change in their characteristic smell.

**Answer:** Observe the odour of the strips after adding the substances.

### Question 2

*2 marks · Very short answer*

Do you notice any change in the odour of the onion strips before and after putting tamarind water and baking soda solution on them?

**Solution**

1. The characteristic smell of onions is retained when an acidic substance like tamarind water is added.
2. The characteristic smell of onions disappears or cannot be detected when a basic substance like baking soda solution is added.

**Answer:** Yes, the odour of onion strips changes in a basic medium (baking soda solution) while it remains unchanged in an acidic medium (tamarind water).

> Common mistake: Confusing the effect of acidic and basic substances on the odour of olfactory indicators.

### Question 3

*Activity*

Note your observations.

**Solution**

1. Record whether the characteristic odour of the onion strips is retained or destroyed upon treatment with acidic and basic substances.

**Answer:** Note down the observations regarding changes in odour.

### Question 4

*Activity*

Similarly, test the change in the odour with other acidic and basic substances and record your observations.

**Solution**

1. Test other substances such as vanilla extract or clove oil with various acids and bases to observe similar changes in odour.

**Answer:** Perform the test with other substances and record observations.

## Related pages

- [All Chapter 2 NCERT solutions](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions)
- [Exercise 2.1](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-1)
- [Exercise 2.2](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-2)
- [Exercise 2.4](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-4)
- [Exercise 2.5](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-5)
- [Exercise 2.7](https://www.swavid.com/science/class/7/chapter/exploring-substances-acidic-basic-and-neutral/ncert-solutions/exercise-2-7)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student