For the Instructor

This textbook is modeled on the Tro textbook map with a few notable exceptions. Changes were made based on the results of student learning outcome assessments in my own courses. More space has been given to some areas where assessment results indicate students need additional learning options. Consequently, less space has been given to some areas where assessment results indicate students were not in need of additional information. This has sometimes meant chapters are combined, spread out, or rearranged. In some cases, material was curated from a different textbook map within the LibreTexts system. A comprehensive list of changes is included towards the end of this section.

I also wanted to share why I have made some of these changes in the way that I did, and what to expect for them. There are two principles which have guided this design: constructivism and iteration. Chemistry is a subject which is best learned iteratively, and this sort of approach has been used in areas where student learning outcomes could improve. The goal here is to take what would normally be a steep learning curve and spreading it out over the course of the semester: stepping away from the subject for a while, and then stepping back into it with more knowledge later, along with a review of what was previously covered. The two concepts for which this approach has been used are stoichiometry and ionic compounds.

In addition to leaving space to touch on stoichiometry at several points throughout the semester, a constructivist approach has been used in the way that it is discussed within the text. Many commercial textbooks have professionally designed graphics to help aid in the dimensional analysis of stoichiometry problems. Although there are some great graphic designs in one of the sources used, most of the time there are not graphic designs within the text to map out the specific aspects of stoichiometry calculations. The initial design is included as an example of how such a graphic could potentially be helpful in deciding on how to solve a problem. When new stoichiometry concepts are introduced, the text will refer back to this graphic and ask students to create their own guide for how to solve the problem. I believe that if students can create their own problem-solving map, it will be more effective than even the most professionally designed graphic.

I would like this textbook to be something that instructors can use even if they have different areas of concern related to student learning outcomes. Because of this, I have sometimes added more material than I might have otherwise. Word count is not a limit for an online text, although of course we need to be aware of realistic expectations for our students. Practically what this will look like is there are some areas where material is duplicated. Sometimes this will be a section with several subsections that go into greater detail followed by a section which covers the same information more succinctly. The idea would be the instructor decides which of these to use in the class: the long version or the short version. In other cases, specifically with stoichiometry, the same concepts are covered in different parts of the text so that an instructor might cover it at different times depending on when they would like to do so.

The following changes are made to the overall organization of the textbook compared to the Tro textbook:

· chapter 1 has been moved to the front matter, and subsequent chapters have been renumbered accordingly.

· Density has been moved from the measurements chapter to the matter and energy chapter.

· A new chapter called elements and compounds combines the chapter on atoms and elements in the chapter on molecules and compounds.

· Solubility has been removed from the chapter on chemical reactions and is addressed in a later chapter. A discussion of double replacement reactions remains in this chapter, without reference to solubility rules. A fuller discussion of precipitation reactions is then added in a later chapter.

· More time is spent on the different possible conversions in the chapter on stoichiometry, and concepts like limiting reactant, theoretical yield and entropy are treated as additional topics which may be covered here or in a later chapter.

· Electrons and chemical bonding are combined into a single chapter.

· A new chapter is created called attractive forces which combines the material in the chapter liquids, solids, and intermolecular forces with the basics of intermolecular forces in solution, as well as revisiting precipitation reactions now that we have a thorough basis for discussing solubility rules.

· References to chemical equilibrium are only included as they are important for acid and base chemistry.

· An additional chapter is created towards the end of the book in which stoichiometry is revisited after having shown stoichiometry applications in gas laws and solutions. The intent is to spend more time here on limiting reagent and percent yield calculations, but if this had previously been covered then the chapter could serve as a review.

Finally, I should mention that creating this textbook was mostly a matter of curation. Most of the words in this text were written by other people. The few times when I did add words were often in the section headings that I have added. In some cases, I took what was a single section in a previous text and divided it into two or more sections for this text. The biggest chunk of text for this book came from the Tro textbook map. In addition, the material from the CK-12 textbook was used extensively, especially related to moles and stoichiometry. Some material was also used from the Ball textbook map. As the Tro textbook map did not have any end of chapter exercises, these were taken from other textbooks, in many cases general chemistry textbooks.