Concept:Hydrogen bonding has strict atomic requirements: a hydrogen atom must be covalently attached to a very small, highly electronegative atom (specifically N, O, or F).
Formula:Not applicable.
Solution:- Ammonia (\( \text{NH}_3 \)) has \( \text{N-H} \) bonds.
- Ethyl alcohol (\( \text{C}_2\text{H}_5\text{OH} \)) has an \( \text{O-H} \) bond.
- Carboxylic acids (\( \text{R-COOH} \)) have an \( \text{O-H} \) bond. All three of these can readily donate and accept strong hydrogen bonds.
- Hydrocarbons (like methane or hexane) consist purely of Carbon and Hydrogen. Because the electronegativity difference between C (2.5) and H (2.1) is extremely small, the bonds are practically non-polar.
- Without highly polarized hydrogens or lone pairs on electronegative atoms, hydrocarbons have zero tendency or capacity to form hydrogen bonds.
Why other options are incorrect:The other options contain functional groups that are textbook examples of hydrogen bond participants.
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