Question

The correct observation in the following reactions is:

• A. Formation of red color
• B. Formation of blue color
• C. Formation of violet color
• D. Gives no color

Answer 1

The correct option is A

Formation of red color

The correct option is (A):
Explanation for the correct answer:

Seliwanoff's reagent:-

1. It is basically used in a chemical test which helps in distinguishing between the aldose and ketose sugars.
2. So if in the solution the ketose group is absent then there will not be any colour change and will be a negative Seliwanoff's test.
3. If the ketose group is present in the solution then it is a positive Seliwanoff's test, the colour will change to cherry red because of the formation of the complex.
4. So on hydrolysis, cleavage of Sucrose will take place which will result in Glucose and Sucrose.
5. And so on prolonged heating, the glucose will transform into fructose by the catalytic action taking place.
6. Fructose is basically a ketohexose which means a ketose, so further on the reaction with Seliwanoff's reagent, there would be the formation of Red colour because of the complex formed.

Therefore, the correct answer is (A):- Formation of red colour.