okay first off, this book is NOT for 1st or second year students. the examples make sense(some of the time) until you get to the problems in the back of the book and then you wonder why you picked chemical engineering as a major in the first place because these problems really makes you feel sort of dumb. im taking the materials and energy balance class and in my school it's used to weed people out. let me say this again, if you are taking a materials and energy balance class and you need a text, do not get this one. i hear a lot of great things from the text basic principles and calculations in chem eng by D.M Himmelblau and J.B Riggs so get that one instead unless your teacher demands you get this book. truly a horrible book to start out a chem eng major.