A Level Chemistry OCR Practice Exam

A functional group in an organic molecule is defined as the part of the molecule that is responsible for its chemical behavior. Functional groups contain specific atoms or groups of atoms that dictate the reactivity and characteristics of the molecule. They are typically associated with particular types of reactions and influence properties such as polarity, acidity, basicity, and overall reactivity.

For example, hydroxyl groups (-OH) indicate that a molecule is an alcohol and will exhibit certain characteristics, such as increased polarity and hydrogen bonding capabilities. Similarly, carboxyl groups (-COOH) identify acids, which have distinct reactive properties due to their ability to donate protons.

Understanding functional groups is essential in organic chemistry, as they provide insight into how different compounds will behave in chemical reactions and under various conditions. This concept is foundational for predicting the behavior of organic molecules and their interactions in biological and chemical systems.