A Textbook of Engineering Chemistry provides an indepth exploration of chemical concepts tailored to engineering applications. This comprehensive guide is structured to support students across diverse engineering disciplines, ensuring they understand the fundamental role chemistry plays in solving technical and industrial challenges. The book begins with an introduction to water treatment, discussing hard and soft water, its implications, and methods for domestic and industrial water treatment. A systematic explanation of the Phase Rule lays a foundation for understanding phase equilibria in single and multicomponent systems. Corrosion, a persistent issue in engineering, is addressed with a focus on its types, mechanisms, and preventive strategies. Fuels and lubricants are explored in detail, emphasizing their classification, properties, and significance in energy and machinery. The electrochemistry chapter provides a detailed overview of conductance, cell potential, and applications like fuel cells. Instrumental methods of analysis introduce readers to modern analytical techniques essential for precise chemical investigations. Subsequent chapters explore engineering materials, polymers, and nanomaterials, shedding light on their composition, properties, and advanced applications in technology. The final chapter, green chemistry, emphasizes sustainable practices and the importance of reducing environmental impact through innovative synthesis methods and carbon sequestration. Written in clear and accessible language, the book blends theoretical concepts with practical applications, including problem-solving exercises and case studies. It is an indispensable resource for engineering students, academics, and professionals seeking a thorough understanding of chemistry in engineering contexts. The book stands as a testament to the interdisciplinary nature of chemistry and its enduring relevance in technological advancements.