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JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Biomolecules

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When sugar 'X' is boiled with dilute in alcoholic solution, two isomers 'A' and 'B' are formed. 'A' on oxidation with yields saccharic acid where as 'B' is laevorotatory. The compound 'X' is :
  1. (A)Maltose
  2. (B)Sucrose✓ Correct
  3. (C)Lactose
  4. (D)Strach

Answer: (B)

Solution

The sugar X undergoes acid hydrolysis to give two monosaccharides A and B. Isomer A yields saccharic acid upon oxidation with , which is characteristic of glucose (D-glucose gives saccharic acid). Isomer B is laevorotatory, which is characteristic of fructose (D-fructose has ). The disaccharide that hydrolyzes to give glucose and fructose is sucrose. Maltose gives two glucose units, lactose gives glucose and galactose, and starch is a polysaccharide. Therefore, X is sucrose.

JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Single correct option

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