What is a functional group? List some examples.

Organic chemistry is a sub-discipline of chemistry that focuses on the study of carbon-containing compounds and their structure, properties, and reactions. Carbon is exceptional due to its ability to form strong covalent bonds with other carbon atoms, creating a wide variety of structures such as chains, rings, and frameworks that are the basis for the complexity of organic molecules.

The significance of organic chemistry stems from the sheer diversity of organic compounds and their central role in life processes. As the chemical basis of all known life, organic chemistry is highly interconnected with biochemistry, medicine, and pharmacology. Understanding functional groups, which are specific clusters of atoms within molecules, is crucial because they largely dictate how organic molecules interact with each other and with other substances.

Chemical reactions involve the transformation of substances through the making and breaking of chemical bonds, leading to the formation of new compounds. In the context of organic chemistry, these reactions often occur at or around functional groups within the molecules.

Each type of functional group undergoes characteristic chemical reactions. For instance, alcohols with hydroxyl groups (-OH) typically engage in dehydration reactions, whereas carboxylic acids with carboxyl groups (-COOH) readily participate in acid-base reactions. These reactions can be categorized as addition, substitution, elimination, and rearrangement reactions. Understanding the reactivity of different functional groups is essential for predicting the outcome of chemical reactions and is a fundamental skill for students of organic chemistry.

The molecular structure refers to the three-dimensional arrangement of atoms within a molecule. It includes not only the spatial arrangement of atoms but also the chemical bonds that hold them together. In organic chemistry, the molecular structure determines the physical properties of a substance (such as boiling point and solubility) and the way it behaves in chemical reactions.

Functional groups are a key component in the molecular structure as they influence the polarity of the molecule and can create sites of reactivity. For example, carbonyl groups (>C=O) make the molecule polar and can lead to nucleophilic addition reactions, while amino groups (-NH2) can engage in hydrogen bonding, affecting both the molecule's reactivity and its physical properties. Studying molecular structure helps students understand how different molecules interact and the mechanisms by which reactions occur.