Which of the following statements is/are correct about H-bonding? (a) \(\mathrm{n}\) -Butanol has a higher boiling point than diethylether on account of intramolecular H-bonding. (b) Maleic acid is a stronger acid than fumaric acid due to the stabilization of the resulting anion by intramolecular H-bonding. (c) \(\mathrm{p}\) -nitrophenol is steam volatile due to intramolecular hydrogen bonding. (d) Hydrogen bond formation intramolecularly involving one molecule only is known as chelation and when formed intermolecularly is known as association.

Intramolecular hydrogen bonding occurs when a hydrogen atom within a molecule forms a bond with another electronegative atom in the same molecule. This type of bonding can lead to the stabilization of a particular structure, such as in Maleic acid where the acid groups can stabilize the anion formed after it loses a hydrogen ion (deprotonation). The stability can enhance the acidity of organic compounds because the molecule can more readily release a hydrogen ion.

An important fact to understand here is that intramolecular hydrogen bonding does not always translate to increased boiling points; for instance, p-nitrophenol is more volatile due to intramolecular bonds, leading to a lower boiling point and enabling it to be steam-volatile. These bonds are strong but confine the bonding to within the molecule, preventing extensive bonding with other molecules which could increase boiling points.

Intermolecular hydrogen bonding, in contrast to the intramolecular type, happens between different molecules. This bond is significantly influential in determining the physical properties of a substance, such as the boiling point. In the example of n-butanol and diethyl ether, n-butanol forms intermolecular H-bonds due to its hydroxyl group, resulting in a higher boiling point compared to diethyl ether which cannot form such bonds.

Intermolecular hydrogen bonds can create networks of molecules, leading to a higher resistance against phase change from liquid to gas, and thus a higher boiling point. Often found in substances like water, this type of bonding is crucial for the unique properties that allow for life-sustaining reactions to occur on Earth.

The boiling point of a compound is determined by the strength of the attractions between its molecules. Hydrogen bonding, being one of the strongest types of intermolecular forces, can significantly increase a substance's boiling point. Molecules that can form intermolecular hydrogen bonds will generally have higher boiling points than those that do not, all else being equal.

This explains why compounds like alcohols, which can form these bonds, typically have higher boiling points compared to ethers of similar molecular weights. The ability of a molecule to form extensive hydrogen bonds with its neighbors will require more energy (heat) to be separated and, consequently, a higher temperature to boil.

The acidity of organic compounds is greatly influenced by the presence or absence of hydrogen bonding. Acids can release a proton (H+), and the ease with which they do so determines their acidity. Intramolecular hydrogen bonding can stabilize the negative charge of the conjugate base that forms when an acid releases a proton.

For example, Maleic acid is more acidic than Fumaric acid because it can form an intramolecular hydrogen bond, which stabilizes the anion formed when the acid donates its proton. This bonding supports the acid's ability to lose a proton, hence, increase its acidity. Moreover, substances with stronger intramolecular bonding tend to be less acidic as the hydrogen is held more tightly within the molecule.