A "coffee-cup" calorimetry experiment is run for the dissolution
of 2.5 g of lithium nitrate placed into 97.2 mL of water. The
temperature of the solution is initially at 23.5 oC. After the
reaction takes place, the temperature of the solution is 28.3
oC.
A) For this process, what is the system and what is the
surroundings?
B) Continuing with the same experiment as in question A, is the system exothermic or endothermic? How can you tell?
A) The system is the calorimeter and the surrounding is everything except calorimeter and its content i.e. outside of calorimeter.
B) The system is exothermic. When system is exothermic it gives out heat. Now calorimeter is completely isolated and hence heat can not go to surroundings. This leads to the heat accumulation inside the calorimeter consequently leading to the temperature rise. With this evidence given that temperature is rising we can safely say that system exothermic.
Get Answers For Free
Most questions answered within 1 hours.