The very favorable response to Chemistry Connections encouraged us to prepare this expanded second edition. We have improved the collection of questions, particularly to enhance the number of applications in the area of organic chemistry. Furthermore, we have revised the organization of questions to assist instructors in selecting examples to coordinate with the principles and topics covered in their chemistry classes. The new organization, photographs, and chapter headings will stream-line the connection with a range of general chemistry textbooks and courses. For the general reader, however, our intention is still to demonstrate the wide scope and significance of chemistry and the ever-present connection of the discipline to our daily lives.