Part -1:
1. Define enthalpy.
2. What is the relationship between the enthalpy of a reaction and its classification as endothermic or exothermic?
3. With instant hot compresses, calcium chloride dissolves in water and the temperature of the mixture increases. Is this an endothermic or exothermic process?
Part -2:
1. Calculate the overall temperature change for the cold and hot pack substance. HINT: This is the difference in the maximum temperature and minimum temperature of each.
Cold pack ΔT:
Hand warmer ΔT:
2. Which pack works by an exothermic process? Use experimental data to support your answer.
3. Which pack works by an endothermic process? Use experimental data to support your answer.
4. Which pack had the greatest change in enthalpy? How do you know?