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(a) Despite having an aldehydic group, g...

(a) Despite having an aldehydic group, glucose does not give 2, 4-DNP test. What does it indicate ?
(b) Draw Haworth structure of `alpha-D(+)` glucopyranose
(c ) What is the significance of D and (+) here ?

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### Step-by-Step Solution #### (a) Why does glucose not give the 2,4-DNP test despite having an aldehydic group? 1. **Understanding the 2,4-DNP Test**: The 2,4-dinitrophenylhydrazine (2,4-DNP) test is used to detect the presence of aldehydes and ketones. A positive test results in the formation of a yellow-orange precipitate, indicating the presence of these functional groups. 2. **Structure of Glucose**: Glucose exists primarily in a cyclic form (pyranose) rather than in its open-chain form. In the cyclic structure, the aldehydic group (which is located at the first carbon in the open-chain form) reacts with the hydroxyl group of the fifth carbon to form a hemiacetal. ...
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