Question

Select the compound from the following that will show intramolecular hydrogen bonding.

• A. \( \text{H}_2\text{O} \)
• B. \( \text{NH}_3 \)
• C. \( \text{C}_2\text{H}_5\text{OH} \)
• D.

  

Answer 1

The Correct Option is D

To identify a compound exhibiting intramolecular hydrogen bonding, one must understand the phenomenon. Intramolecular hydrogen bonding occurs within a single molecule when a hydrogen atom attached to a highly electronegative atom (e.g., oxygen, nitrogen, fluorine) forms a bond with a lone pair of electrons on another electronegative atom within the same molecule. This typically results in a five or six-membered ring formation.

Consider the provided options:

• \(\text{H}_2\text{O}\): Water molecules form intermolecular hydrogen bonds between separate molecules, not intramolecular ones.
• \(\text{NH}_3\): Ammonia participates in intermolecular hydrogen bonding with other ammonia molecules, not intramolecular bonding.
• \(\text{C}_2\text{H}_5\text{OH}\): Ethanol can form hydrogen bonds, but these are intermolecular. The hydroxyl hydrogen bonds with the oxygen of another ethanol molecule.
• The fourth option is represented by an image of a compound:

The compound shown in the image is characteristically salicylaldehyde or orthonitrophenol. These compounds possess a hydroxyl group (–OH) and an adjacent electronegative group, such as an aldehyde (–CHO) or nitro (–NO₂). In these structures, the hydrogen atom of the hydroxyl group can form a hydrogen bond with the lone pair of electrons on the adjacent electronegative atom, leading to intramolecular hydrogen bonding.

Conclusion: The compound depicted in the image is correctly identified as capable of intramolecular hydrogen bonding. Therefore, the correct answer corresponds to the compound represented by the image with data-src-id="67347e092f20741705a5c770".