Mass transfer operations are of great importance in a process industry as it has a direct impact on the cost of the final product. A chemical/process engineer therefore should have sound knowledge of the basics of mass transfer and its applications. This book is designed to equip the reader with sufficient knowledge of mass transfer operations and face the challenges ahead. The objective of this textbook is to teach a budding chemical engineer the principles involved in analyzing a process and apply the desired mass transfer operation to separate the components involved. It deals with operations involving diffusion, interphase mass transfer, humidification, drying, crystallization, absorption, distillation, extraction, leaching and adsorption. The principles and equipment used for different mass transfer operations have been lucidly explained. Designed for a two-semester course, this text is primarily intended for the undergraduate students of chemical, pharmaceutical, petrochemical engineering as well as biotechnology and industrial biotechnology. It will also be useful to plant engineers and design professionals. Key features: 1. Explains the theoretical concepts with full derivation of equations. 2. Illustrates the application of theory through worked-out numerical examples. 3. Provides exercise problems with answers at the end of each chapter for practice.