Do we have to worry about chemical reactions when formulating?

If you know me by know I am quite into chemistry. I am getting a Bachelor of Science in Chemistry. Right now I am at a community college in my second semester of organic chemistry. Organic chemistry is quite hard, but it is quite rewarding. It is all the chemistry of our raw material, and how they are made. My first semester, with a month left, my professor had to go on medical leave. So it was quite hard to learn the last month. So, I am trying to build up my resources so that I can take the final exam. For my college the final exam is the American Chemistry Society's (ACS) exam. It is one of those standardized exams.