Question

1. would you use reaction 1 or reaction 2 if you were constructing a device that became cold to the touch? explain your answer.

Explanation:

An endothermic reaction absorbs heat from the surroundings. In Reaction 2, the temperature of the system decreases (as seen from the graph going down), which means it is absorbing heat from the surroundings (the device itself and the area around it). So the device would become cold to the touch as it loses heat to the endothermic reaction. In Reaction 1, the temperature of the system increases, indicating an exothermic process (releasing heat, so the device would be warm or hot, not cold).

Answer:

Reaction 2. Because in an endothermic reaction (which makes the device cold), heat is absorbed. Reaction 2 shows a decrease in temperature (system absorbs heat from surroundings like the device), while Reaction 1 shows an increase (exothermic, heat - releasing).