In this post, you will find Class 10 NCERT Science Activity 2.2 Explanation in detail. This activity is based on chapter 2 Acids, Bases and Salts of class 10 science.
Class 10 NCERT Science Activity 2.2 Explanation
Activity- Take some finely chopped onions in a plastic bag along with some strips of clean cloth. Tie up the bag tightly and leave it overnight in the fridge. The cloth strips can now be used to test for acids and bases.
· Take two of these cloth strips and check their odour.
· Keep them on a clean surface and put a few drops of dilute HCI solution on one strip and few drops of dilute NaOH solution on the other.
· Rinse both cloth strips with water and again check their odour.
· Note your observations.
· Now take some dilute vanilla essence and clove oil and check their odour.
· Take some dilute HCI solution in one test tube and dilute HCI and dilute NaOH solutions and record your observation.
Observations:
In the above activity the following
observations have been observed-
Onion: Onion has a peculiar smell due to the presence of Sulphurous allium. The smell of
onion diminishes in a base because it reacts like acid and remains as it is in acid.
Vanilla essence: Vanilla
has a pleasant odour due to the presence of an aldehyde and this is a weak acid so the
odour of vanilla essence disappears when it is added to a base. The odour of vanilla essence persists when it
is added to an acid.
Clove Oil:
In bases, its characteristic smell cannot be detected.
Conclusion:
The olfactory indicators change the odour in acidic and basic mediums.
Related Topics -
1. Next activity - Activity 2.3
2. Previous activity - Activity 2.1
4. Extra Questions of Chapter 2
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