A reaction takes place in a bomb calorimeter. if the calorimeter decreases in temperature over the course of the reaction, what are the signs of qcal and qrxn?

qcal would have a sign of (-) as it lost energy resulting to a decrease in temperature, while qrxn would have a sign of (+) as it gained energy. This complies with the Law of Conservation of Energy. The reaction is probably endothermic.