Question

A 0.50-kg piece of aluminum at 250°C is dropped into 1.0 kg of water at 20°C. After equilibrium is reached, what is the net entropy change of the system?

a) Positive value
b) Negative value
c) Zero
d) None of these

Answer 1

The net entropy change of the system will be a positive value.

Step-by-step explanation:

The net entropy change of the system can be determined by considering the entropy change of the aluminum, the water, and the surrounding environment.

Entropy is a measure of the disorder or randomness of a system. When the aluminum is dropped into the water, heat is transferred from the aluminum to the water until they reach thermal equilibrium. This heat transfer increases the entropy of the water, as the water molecules become more randomized with higher kinetic energy. At the same time, the aluminum loses heat, causing its entropy to decrease.

Since the overall entropy change of the system is the sum of the entropy changes of the aluminum and the water, and these changes have opposite signs, the net entropy change of the system will depend on which change is larger. In this case, the water has a greater mass and undergoes a greater temperature change, resulting in a larger entropy change compared to the aluminum. Therefore, the net entropy change of the system will be a positive value.