Organic Chemistry - SS1 Chemistry Past Questions and Answers - page 4

Functional groups are specific groups of atoms within organic molecules that determine their chemical properties and reactivity. They play a crucial role in organic chemistry because they define the behaviour and reactions of organic compounds. By identifying and understanding functional groups, chemists can predict the properties, reactions, and intermolecular interactions of organic molecules, facilitating the synthesis of new compounds and the understanding of their biological activities.

The hydroxyl functional group (-OH) is characterised by the presence of an oxygen atom bonded to a hydrogen atom. It imparts several important properties to organic compounds. The hydroxyl group is polar, making compounds containing it capable of forming hydrogen bonds with other molecules or functional groups. This leads to higher boiling points, solubility in water, and increased intermolecular forces. The presence of a hydroxyl group also renders compounds capable of acidic or basic behaviour, depending on the surrounding functional groups. Additionally, the hydroxyl group can participate in various chemical reactions, such as dehydration to form ethers, esterification to form esters, and oxidation to form aldehydes or carboxylic acids.

The carbonyl functional group (C=O) is one of the most important and versatile functional groups in organic chemistry. It consists of a carbon atom doubly bonded to an oxygen atom. The presence of the carbonyl group imparts distinctive properties and reactivity to organic compounds. It gives rise to the polarity of the C=O bond, making compounds containing it more reactive towards nucleophiles. The carbonyl group is responsible for several important classes of organic compounds, including aldehydes, ketones, carboxylic acids, and esters. It participates in reactions such as nucleophilic addition, condensation, and oxidation-reduction reactions. The carbonyl group also plays a vital role in biological processes, such as enzymatic catalysis and the formation of peptide bonds in proteins.