Finishing Redox with Cyanotypes

Chemistry students are finishing this year with redox reactions (very basic redox) in the context of electrochemical cells. They learn about oxidation numbers, half reactions, reducing/oxidizing agents, and predicting cell potential from reduction tables. It's a lot of conceptual work as well as application. They do well because I have some good hands on labs, but it's a lot to push through. I've been trying to get more creative work into my class (see the adopt an atom post) and redox is a good time to do some cyanotype paper. It's a pretty complicated reaction, so I really simplify the chemistry in order to connect it to the unit. We start by looking at this simplified equation: Groups talk about which atoms are changing and how they know. Once we identify the oxidizing and reducing species, I give a break talk over iron's reduction and interaction with the ferrocyanide anion, which forms an insoluble blue color. The point of this lab isn't to have them internalize and describe…