Question 20

Boojho, Paheli and their friend Golu were provided with a test tube each containing China rose solution which was pink in colour. Boojho added two drops of solution ‘A’ in his test tube and got dark pink colour. Paheli added 2 drops of solution ‘B’ to her test tube and got green colour. Golu added 2 drops of solution ‘C’ but could not get any change in colour. Suggest the possible cause for the variation in their results.

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Solution

China rose is an acid-base indicator.
China rose in different medium shows following reactions:
China rose + acid $⟶$ gives dark pink colour, hence solution 'A' is acidic in nature.
China rose + base $⟶$ gives green colour, hence solution 'B' is basic in nature.
China rose + neutral $⟶$ no change in colour, hence solution 'C' is neutral in nature.

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