Activity 4.7 NCERT Class 10 Science, Carbon and its Compounds

Activity 4.7 NCERT Class 10 Science, Carbon, and its Compounds

Brief procedure:

Activity 4.7 asks us to compare the PH of dilute acetic acid and dilute Hydrochloric acid using litmus paper and universal paper.

Observation: 

Acetic acid is a weak acid. Its PH range is 2 to 4. A typical,1M solution of acetic acid has a PH of 2.4. So on litmus paper, it shows a red-yellow colour. See activity 2.11.

Hydrochloric acid is a strong acid. It’s 0.1M solution has a PH of 1. It shows an utterly red colour with litmus paper.

Universal PH indicator: 

A universal indicator is a mixture of various PH indicators which give sharp colour at different PH.

Here HCL gives red colour and acetic acid gives yellow.

Next: Activity 4.8 Esterification of alcohol.

Ref: Univeral indicator Wikipedia.