Answer
See answer below.
Work Step by Step
a) System: the furnace. Surroundings: everything else, including the house.
Since combustion is exothermic, from the system to the surroundings.
b) System: the water drops. Surroundings: everything else, including your skin.
Evaporation is endothermic so the system takes energy from the surroundings, cooling your skin.
c) System: the water. Surroundings: everything else, including the refrigerator.
Cooling and freezing are endothermic so the system takes energy from the surroundings.
d) System: the flask with the mixture. Surroundings: everything else, including the laboratory bench.
The reaction releases heat so the system loses energy to the surroundings.
