Which of the following functional groups is present in essential oils?

Essential oils are complex mixtures of volatile compounds, and various functional groups contribute to their therapeutic properties and aromatic profiles. Among the functional groups present in essential oils, esters and aldehydes are commonly found.

Esters are significant components in many essential oils, contributing to fruity scents and relaxing effects. They are formed through the reaction of acids and alcohols and play a key role in the fragrance industry. For instance, they are prevalent in oils such as bergamot and sweet orange.

Aldehydes, another important functional group, are known for their distinctive odors and potential health benefits. They can impart fresh, uplifting aromas and may possess antimicrobial properties. Essential oils like lemon and citronella contain these compounds.

The presence of both esters and aldehydes in essential oils signifies their importance in aromatherapy. These functional groups enhance the therapeutic effects of the oils, making the answer that includes both correct. This reflects the diversity of constituents within essential oils and how they can provide various aromatic and medicinal benefits in holistic practices.