These are 3 VERY FUNNY problems that require your student to use thermochemistry knowledge to solve them. They are entertaining, but they also give your students a chance to see if they know when to use Hess' Law as opposed to using Heats of Formation (in a products-reactants equation) to find the solution. When they've figured out the answer, they scan a QR code to confirm. Don't like QR codes? I've included a set of these same problems without QR codes for you to use instead.
This product comes in WORD format, so it's easily edited to meet your needs. It includes detailed answer keys and QR codes that link to keys online.