(a) Write the structural formulas of diethyl ether and 1-butanol (note that they are isomers). (b) The boiling point of 1-butanol is \(117^{\circ} \mathrm{C}\), higher than that of diethyl ether \(\left(35^{\circ} \mathrm{C}\right)\), yet the solubility of both compounds in water is about \(8 \mathrm{~g}\) per \(100 \mathrm{~mL}\). Account for these observations.

Isomers are molecules that share the same molecular formula but differ in the arrangement of atoms within the molecule. This property creates compounds with distinct physical and chemical characteristics even though they are made up of the same types of atoms. For instance, diethyl ether and 1-butanol are both composed of the elements carbon (C), hydrogen (H), and oxygen (O), and have the same molecular formula, C₄H₁₀O. However, their structures are different: diethyl ether has an oxygen atom linking two ethyl groups, while 1-butanol is a straight-chain alcohol with a hydroxyl group attached to the end carbon.

Understanding isomers is crucial for students because it lays the foundation for studying organic chemistry, where slight differences in structure translate to different biological functions and chemical behaviors.

Boiling point is a characteristic physical property of a substance that can provide insight into the molecular interactions present within the compound. Comparing the boiling points of isomers like diethyl ether and 1-butanol (117°C and 35°C, respectively), highlights the influence of molecular forces.

The higher boiling point of 1-butanol arises from the strong hydrogen bonds formed between its hydroxyl group and other molecules, which require more energy to break when compared to the relatively weaker van der Waals forces found in diethyl ether molecules. This example demonstrates how structural differences in isomers lead to significant disparities in their boiling points.

Solubility in water is another key concept for understanding organic compounds. It's influenced by the ability of a compound to form hydrogen bonds with water molecules. Both diethyl ether and 1-butanol have parts of their structures that can engage in hydrogen bonding due to the presence of oxygen atoms, explaining why they have similar levels of water solubility at about 8 g per 100 mL.

However, the remainder of their structures consists of hydrocarbon chains, which are nonpolar and hydrophobic, limiting their solubility. The balance between hydrogen-bonding regions and hydrophobic regions leads to comparable solubility characteristics for these two isomers, despite the differences in their overall boiling points.

Hydrogen bonding is a particularly strong type of dipole-dipole interaction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom like oxygen, nitrogen, or fluorine, and is in close proximity to another electronegative atom.

In the case of 1-butanol, the hydroxyl group (OH) forms hydrogen bonds leading to higher boiling points due to increased intermolecular attraction. On the other hand, diethyl ether lacks this hydrogen bonding capability because it does not have a hydrogen atom bonded to its oxygen atom, resulting in a significantly lower boiling point. Hydrogen bonding not only affects boiling point but also other properties such as solubility and melting point, making it a fundamental concept in the study of organic chemistry.