Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : The property of invert sugar is that it does not crystallise.
Reason (R) : Sugar hydrolyses in the presence of acid to form glucose and fructose which is called invert sugar

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true and (R) is not the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Invert sugar is a key ingredient in making candies and jams because its glucose-fructose mixture prevents gritty sugar crystals from forming during storage.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Sucrose (table sugar) can be hydrolyzed into its constituent monosaccharides, glucose and fructose, in the presence of heat and acid.
This resulting equimolar mixture is called invert sugar, which exhibits different physical and chemical properties than sucrose.

Step 2: Detailed Explanation:
Let us evaluate the Assertion and Reason:
- Reason (R): "Sugar hydrolyses in the presence of acid to form glucose and fructose which is called invert sugar."
This is scientifically true.
The acid-catalyzed cleavage of the glycosidic bond in sucrose yields glucose and fructose, which is termed invert sugar because it rotates polarized light in the opposite direction compared to sucrose.
- Assertion (A): "The property of invert sugar is that it does not crystallise."
This is also true.
Invert sugar has a much lower tendency to crystallize than sucrose.
The presence of a mixture of glucose and fructose molecules interferes with the orderly alignment required to form sucrose crystals.
Additionally, fructose is highly hygroscopic (holds moisture), which helps prevent crystallization.
- Since the chemical formation of invert sugar (hydrolysis of sucrose into glucose and fructose) directly explains why it resist crystallization, Reason (R) is the correct scientific explanation of Assertion (A).
Therefore, Option (A) is correct.

Step 3: Final Answer:
Both Assertion (A) and Reason (R) are true, and (R) is the correct explanation of (A).