To identify the alcohol with the lowest boiling point, consider the impact of molecular weight and intermolecular forces. Alcohols form hydrogen bonds via their hydroxyl (-OH) groups, a potent dipole-dipole interaction. In a homologous series, boiling point typically rises with molecular weight due to increased surface area, enhancing London dispersion forces.
Examining the provided alcohols:
The observed boiling point trend is predominantly dictated by molecular weight and the increased contact points resulting from longer alkyl chains:
Based on this evaluation, methanol exhibits the lowest boiling point. This is attributed to its minimal molecular structure, resulting in weaker London dispersion forces, even though all listed alcohols participate in hydrogen bonding. Consequently, methanol's lowest molecular weight and comparatively reduced intermolecular attractions yield the lowest boiling point among these alcohols.