Question:medium

Given below are two statements:
Statement I: Sucrose is dextrorotatory. However, sucrose upon hydrolysis gives a solution having mixture of products. This solution shows laevorotation.
Statement II: Hydrolysis of sucrose gives glucose and fructose. Since the laevorotation of glucose is more than the dextrorotation of fructose, the resulting solution becomes laevorotatory.
In the light of the above statements, choose the correct answer from the options given below.

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Hydrolysis of sucrose produces invert sugar, which is laevorotatory due to the dominant optical rotation of fructose.
Updated On: Mar 29, 2026
  • Statement I is false but Statement II is true
  • Statement I is true but Statement II is false
  • Both Statement I and Statement II are false
  • Both Statement I and Statement II are true
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The Correct Option is D

Solution and Explanation

To determine the correctness of the given statements regarding sucrose and its hydrolysis, we need to understand the chemical behavior of sucrose, glucose, and fructose.

Statement I: "Sucrose is dextrorotatory. However, sucrose upon hydrolysis gives a solution having a mixture of products. This solution shows laevorotation."

  • Sucrose is indeed dextrorotatory, meaning it rotates plane-polarized light to the right.
  • Upon hydrolysis, sucrose breaks down into glucose and fructose. The chemical reaction is as follows: \(\text{C}_{12}\text{H}_{22}\text{O}_{11} + \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6(\text{glucose}) + \text{C}_6\text{H}_{12}\text{O}_6(\text{fructose})\)
  • Glucose is dextrorotatory, while fructose is laevorotatory.
  • The specific rotation of fructose is higher in magnitude than that of glucose but in the opposite direction, so the resulting solution of glucose and fructose after hydrolysis is laevorotatory.

Hence, Statement I is true.

Statement II: "Hydrolysis of sucrose gives glucose and fructose. Since the laevorotation of glucose is more than the dextrorotation of fructose, the resulting solution becomes laevorotatory."

  • This statement correctly describes the outcome of sucrose hydrolysis and the optical activity of the solution formed.
  • The specific rotation of fructose is approximately -92° while that of glucose is around +52.5°.
  • The net rotation of the mixture of glucose and fructose will be laevorotatory because the effect of fructose is more significant than that of glucose.

Thus, Statement II is true as well.

Conclusion: Both statements are correct because they correctly describe the chemistry of sucrose hydrolysis and the resulting optical activity of the solution.

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