We have to teach a lot of topics in a given year. I don't know of a single teacher who didn't wish they had more time in the year to cram in a few more of the items that we stuffed into the textbook/curriculum. If I could create the perfect chemistry class, it would focused around chemical reactions--as much is physically possible. Chemistry is a lab science in which we study the interaction of molecules in a variety of scenarios. Yet, an inordinate amount of my time is spent teaching math. Not just teaching math, but trying to come up with real-world examples of the math to develop "meaning" for my students' question of "Why do we need to know this?" I understand real-world examples are important, but if I have to manufacture examples, maybe the information isn't meaningful in the first place?
This coming school year we have a challenge. We are shifting to an A/B Block which actually reduces the time in class by 88 minutes per week, but are not modifying the curriculum nor the district-wide exams. Some teachers turned to the textbook and started looking at what chapters could be shrunk or cut. I took a slightly different approach to the problem.
One of biggest pet peeves is "teaching math" inside of chemistry. While there are obvious places it is necessary (stoichiometry, moles, solutions because they all relate to chemistry), there is one place it is not and that's Dimensional Analysis. You remember this: I give you a measurement in feet and ask you how many nanometers it is. Where's the chemistry in this? What purpose does this serve in either my class or the real world? I used say things like "Well, if a person walked up to you on the street and held a gun to your head and said 'Perform the following metric conversion' you would be able to do it", but that's ridiculous. In today's world, if someone actually did that, I would pull out my phone and GOOGLE THE ANSWER!! I have a friend who is an actual scientist for a pharmaceutical company and he hasn't performed a metric conversion since he took Physics back in college 14 years ago!
So, why do we continue to teach topics that have no relevance in both our curriculum and the real-world?
Please don't let the answer be "because it is in the textbook."