Organic chemistry is the branch of chemistry that deals with the study of hydrocarbons and their derivatives. Functional Group: The functional groups are atom or group of atoms joined in a specific manner which determines the chemical properties of the organic compound. In the chapter “Organic Chemistry – Some Basic Principles and Techniques” of class 11 Chemistry, students are introduced to topics like classification, nomenclature, purification and qualitative analysis of organic compounds, isomerism, organic reaction and more.