Entropy True or False?

Question

Which of the following statements is true (T) or false (F):
(a) All real processes are irreversible
(b) In an irreversible cyclical process, the system returns to its original state, but the universe does not.
(c) All spontaneous processes increase the disorder of the system

Answer 1

(a) yes In order to be reversible a process must be very slow

(b) True. When irreversible process, the entropy rises

(c) True also. they are mainly irreversible

Answer 2

a. true
b. false
c. true


moreover

The concept of entropy in thermodynamics is central to the second law of thermodynamics, which deals with physical processes and whether they occur spontaneously. Spontaneous changes occur with an increase in entropy. Spontaneous changes tend to smooth out differences in temperature, pressure, density, and chemical potential that may exist in a system, and entropy is thus a measure of how far this smoothing-out process has progressed. In contrast, the first law of thermodynamics deals with the concept of energy, which is conserved. Entropy change has often been defined as a change to a more disordered state at a molecular level. In recent years, entropy has been interpreted in terms of the "dispersal" of energy. Entropy is an extensive state function that accounts for the effects of irreversibility in thermodynamic systems.

Quantitatively, entropy, symbolized by S, is defined by the differential quantity dS = δQ / T, where δQ is the amount of heat absorbed in a reversible process in which the system goes from one state to another, and T is the absolute temperature.[3] Entropy is one of the factors that determines the free energy of the system.

When a system's energy is defined as the sum of its "useful" energy, (e.g. that used to push a piston), and its "useless energy", i.e. that energy which cannot be used for external work, then entropy may be (most concretely) visualized as the "scrap" or "useless" energy whose energetic prevalence over the total energy of a system is directly proportional to the absolute temperature of the considered system. (Note the product "TS" in the Gibbs free energy or Helmholtz free energy relations).

In terms of statistical mechanics, the entropy describes the number of the possible microscopic configurations of the system. The statistical definition of entropy is generally thought to be the more fundamental definition, from which all other important properties of entropy follow. Although the concept of entropy was originally a thermodynamic construct, it has been adapted in other fields of study, including information theory, psychodynamics, thermoeconomics, and evolution.[4][5][6]