For each of the following cases, define the closed system, write down the energy balance for the system, simplify the energy balance equation based on the information given, and state whether heat and work terms are positive or negative:
a) a tray filled with water at 25°c is put into a freezer and the water turns into ice at -10°c. (7 points)
b) a chemical reaction takes place in a closed adiabatic reactor. (7 points)
c) a chemical reaction is carried out in an isothermal reactor. assume that when the reaction took
place in the adiabatic reactor, the temperature in the reactor increased. (7 points)