Hydrogen bonding with water: what does it imply about the solute? A compound capable of forming hydrogen bonds with water typically has which key bonding characteristic?

Introduction / Context:
Solubility and interactions of biomolecules in water depend on polarity and hydrogen bonding. Many metabolic intermediates and drug molecules rely on hydrogen bonding to achieve adequate aqueous solubility and specific binding.

Given Data / Assumptions:

• We consider typical small molecules or functional groups in biology.
• Hydrogen bonding requires appropriate donors/acceptors.
• Medium is water (a strong hydrogen-bonding solvent).

Concept / Approach:
Hydrogen bonds form when a hydrogen attached to an electronegative atom (N, O, sometimes S) interacts with a lone pair on another electronegative atom. Such atoms are created by polar covalent bonds (for example, O–H, N–H, C=O). Therefore, the presence of polar covalent bonds is a prerequisite for forming hydrogen bonds with water.

Step-by-Step Solution:
Identify hydrogen-bond donors: X–H where X is O or N.Identify hydrogen-bond acceptors: atoms like O or N with lone pairs (for example, carbonyl oxygen).Conclude that polar covalent bonds (unequal electron sharing) enable these interactions.

Verification / Alternative check:
Alcohols, amides, and carboxylic acids show high water miscibility due to H-bonding, while hydrocarbons without polar bonds do not.

Why Other Options Are Wrong:
Noncovalent bonds do not describe intramolecular structure; buffers require conjugate acid–base pairs, not merely H-bond capacity; insolubility contradicts typical H-bonding behavior; purely ionic compounds interact differently and may dissolve without H-bonding donors/acceptors.

Common Pitfalls:
Assuming any electronegative atom guarantees solubility; overall solubility also depends on hydrophobic surface area.

Final Answer:
Contains at least some polar covalent bonds.