Engineering chemistry is taught as a compulsory subject to first year undergraduate students of all the branches of engineering. The scope of the subject is very wide and writing a book for students from varied backgrounds across the country was a challenging assignment. The diverse needs of the students induced us to incorporate a combination of both traditional topics and the latest trends in the subject which include emerging areas such as Water and its treatment, Alloys, Fuels, Batteries and Nanochemistry. This book has been organized to meet the syllabi requirements of almost all Indian universities. The aim of this text is to enable the student to develop capabilities in self learning and understanding. It is a student oriented book and our teaching experience, stretching more than two decades, gave us an insight into the mental status of the students at this level and the problems they confront while studying the subject. Two important facts have been kept in mind: one, students reading this text are taking their first steps into the world of technical education and two, that English is a second language for most of these students.