Here’s a quiz I created to help students train balancing reactions. It’s relatively quick, but it can be rather tricky.
Making the quiz, I decided I needed a more powerful tool for writing out the reactions. I ended up going for the open source program, Inkscape, because it allows me to make the text look precisely the way I wanted. Then I exported it as png, and uploaded that as a question. I did something similar with the answers for some of the questions.