AP Chemistry Question?

Question

I know that q = Delta T X mass X specific heat (4.18)

Negative Delta T means that the reaction is endothermic because the final heat is less than the initial heat. For a Cool reaction, which is endothermic, the Initial Temperature was 25.5 degrees Celsius and the Final Temperature was 0 degrees Celsius so the environment cooled down because the reaction absorbed heat. If you plug in this negative delta T to the q formula, it yields a negative q. A negative q means that the reaction is exothermic which disproves what delta T tells us by being negative. Can you please explain this as I do not understand it AT ALL? thanks!

Hey, I was thinking about it more... Is q the measure of energy RELEASED? So a negative q would mean that the reaction was endothermic.

Answer 1

I know exactly how confusing this is. In the UK, I teach my pupils that the safest way of getting the correct sign for Q is to do "initial temperature minus final temperature", and not the other way round. This makes exothermic reactions have a negative sign, and endothermic ones a positive sign.