Question

Invert sugar.

Hint:

Honey is a natural source of invert sugar, making it sweeter than regular table sugar.

Answer 1

Step 1: Conceptual Overview:
Inversion refers to the change in the sign of optical rotation that occurs during the hydrolysis of sucrose. This process leads to the formation of a mixture that exhibits different optical properties compared to the original substance.
Step 2: Detailed Explanation:
Sucrose is initially dextrorotatory, meaning it rotates plane-polarized light to the right by \( +66.5^\circ \).
Upon hydrolysis, sucrose breaks down into an equimolar mixture of D-(+)-glucose (\( +52.5^\circ \)) and D-(-)-fructose (\( -92.4^\circ \)).
The optical rotation of fructose is more negative (levorotatory) than the optical rotation of glucose (dextrorotatory). As a result, the overall optical rotation of the mixture becomes levorotatory, with a net rotation of \( -39.9^\circ \).
This mixture, which has a negative optical rotation, is known as invert sugar. It is called "invert" because the optical rotation has inverted (switched direction) from the original dextrorotatory sucrose.
Step 3: Final Conclusion:
Invert sugar is the levorotatory mixture of glucose and fructose obtained by hydrolyzing dextrorotatory sucrose.