b) Define entropy? Explain the physical concept of entropy.
Answers
Explanation:
Entropy, the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, the amount of entropy is also a measure of the molecular disorder, or randomness, of a system.
The disorder or degree of randomness in a system is expressed by a thermodyanic function called entropy. Entropy is simply a measure how much the energy of atoms and molecules become more spread out in a process and can be defined in terms of statistical probabilities of a system or in terms of the other thermodynamic quantities.
The change in entropy during a process is defined as the ratio of the heat absorbed by the system isothermally and reversibly to the temperature at which it is absorbed.
∆S = q(rev)/T
More the heat absorbed by the system, more disorder it becomes.
The physical meaning of entropy lies in the ability to provide a measure for degree of disorder or randomness of the system.
In general, in going from solid to liquid and liquid to gases, the disorder and hence entropy increases.
Answer:
Entropy, the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, the amount of entropy is also a measure of the molecular disorder, or randomness, of a system.