An N-HNN hydrogen bond is weaker thiun an \(\mathrm{O}-\mathrm{H}-\mathrm{O}\) hydrogen bond because the difference in electronegativity hetween nitrogen and hydrogen \((3.0\) \(2.1=0.9)\) is less than that between oxygen and hydrogen \((3.5-2.1-1.4)\). The ef= fect of intermolecular hyvlrogen bonding can be illustrated by comparing the boiling points of methylamine and methamol. Both are polar molecules and interact in the pure liquid hy hydroggen bonding. Because hydrogen bonding is stronger in methanol than in methylamine, methanol has the: higher boiling point.

Electronegativity represents the tendency of an atom to attract electrons towards itself when bonded in a molecule. It's a fundamental concept in chemistry that helps explain many molecular behaviors, including bond strength and polarity.

When considering hydrogen bonding, the difference in electronegativity between hydrogen and the other atom it's bonded to is crucial. Typically, a greater difference means a stronger pull on the shared electrons, leading to a more polar bond. This polarity is what makes hydrogen bonding possible. In the case of nitrogen and hydrogen, the difference is 0.9, while for oxygen and hydrogen, it's 1.4, signifying a more potent attraction and hence a stronger hydrogen bond in the latter.

Intermolecular forces are the forces that mediate interaction between molecules, including forces of attraction or repulsion which act between molecules and other types of neighboring particles.

Hydrogen bonds are a type of intermolecular force and are particularly strong because they involve a hydrogen atom bonded to a highly electronegative atom (such as N, O, or F). These forces are essential in determining the physical properties of a substance, like boiling point and melting point. The stronger the intermolecular forces, the more energy is required to overcome these interactions and change the physical state of a substance.

Boiling points provide a key insight into the strength of intermolecular forces within a substance. It's the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid, causing the liquid to turn into vapor.

A higher boiling point indicates that more energy is required to break the intermolecular forces. In the context of hydrogen bonds, the stronger these bonds are within a substance, the higher the boiling point will be. Thus, the boiling point is a practical demonstration of the underlying intermolecular interactions, with methanol showcasing a higher boiling point over methylamine due to stronger hydrogen bonds.

Understanding the difference between methylamine (CH3NH2) and methanol (CH3OH) in terms of their boiling points is an excellent demonstration of intermolecular hydrogen bonding. Both compounds have the ability to form hydrogen bonds, yet the key difference lies in the atoms involved.

Methanol contains an O-H bond, which, due to a larger electronegativity difference, leads to stronger hydrogen bonds compared to the N-H bonds in methylamine. This difference results in methanol having a higher boiling point, reflecting the greater energy required to break these stronger interactions in the liquid state before transitioning into a gas.