Draw the condensed structural formula, or line-angle formula if cyclic, for each of the following:
a. propyl alcohol

A condensed structural formula is a way of representing a chemical compound that shows the arrangement of atoms and the connectivity between them without depicting all the bonds explicitly. In this format, groups of atoms are often grouped together to simplify the representation, making it easier to visualize the molecular structure. For example, propyl alcohol can be represented as CH3-CH2-CH2-OH, indicating the presence of a hydroxyl group (-OH) attached to a three-carbon chain.

The line-angle formula, also known as the skeletal formula, is a shorthand representation of organic molecules where vertices represent carbon atoms and lines represent bonds. This method omits hydrogen atoms attached to carbons, simplifying the drawing of complex structures, especially cyclic compounds. For cyclic structures, the line-angle formula allows for a clear depiction of the ring's shape and connectivity without cluttering the diagram with hydrogen atoms.

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In the case of propyl alcohol, the functional group is the hydroxyl group (-OH), which defines it as an alcohol. Understanding functional groups is essential for predicting the behavior and reactivity of organic compounds, as they influence properties such as solubility, acidity, and reactivity.