Question

Glucose reacts with \( X \) number of molecules of phenylhydrazine to yield osazone. The value of \( X \) is:

• A. three
• B. two
• C. one
• D. four

Hint:

In the formation of osazones, reducing sugars like glucose react with phenylhydrazine. The number of molecules of phenylhydrazine required depends on the number of reactive groups in the sugar, which for glucose is three.

Answer 1

The Correct Option is A

When glucose reacts with phenylhydrazine, it forms an osazone. Glucose, being an aldose sugar, contains both an aldehyde group and a hydroxyl group. The formation of an osazone involves the reaction of glucose with phenylhydrazine at both the aldehyde group and one of the hydroxyl groups. Glucose undergoes a reaction with three molecules of phenylhydrazine to form the corresponding osazone, which is a crystalline compound. This is a characteristic feature of reducing sugars like glucose, which form osazones in the presence of excess phenylhydrazine. 
Thus, the value of \( X \) is \( \boxed{3} \).