Question

"How does Volume affect change in entropy (∆S)?"

a) Volume has no effect on ∆S.
b) Increasing volume generally leads to an increase in ∆S.
c) Increasing volume generally leads to a decrease in ∆S.
d) The effect of volume on ∆S depends on temperature.

Answer 1

Increasing volume typically results in a rise in entropy because a larger volume allows for a greater number of microstates and a higher degree of randomness within the system, leading to greater entropy.

Step-by-step explanation:

When considering the effect of volume on change in entropy (ΔS), option b) Increasing volume generally leads to an increase in ΔS, is the correct answer. This is because entropy is a measure of the randomness or disorder within a system. As volume increases, there are more ways to arrange the particles within a substance, leading to a greater number of microstates and a higher entropy. For gaseous systems, for example, an increase in volume at constant temperature means that the gas particles have more space to spread out, which directly results in an increase in entropy.

When we observe phase changes, the transition from solid to liquid to gas with increasing temperature includes volume expansion and this sequence aligns with an increase in entropy (Ssolid < Sliquid < Sgas). Furthermore, as temperature increases, the volume of a gas also generally increases, which in turn increases its entropy.

In summary, an increase in volume tends to disperse the energy within a system more widely, and according to the second law of thermodynamics, entropy increases when energy is spread out in a system. Therefore, volume expansion is usually associated with an increase in the entropy of the system.