Question

Why Entropy is a state function?

Answer 1

A state function, also known as a function of state or a point function, is a function defined for a system that connects several state variables or state quantities and is dependent only on the system's current equilibrium thermodynamic state (e.g. gas, liquid, solid, crystal, or emulsion), not on the path it took to get there. A state function specifies a system's equilibrium state, as well as the kind of system.

Complete answer:
Entropy is a quantifiable physical characteristic that is most frequently linked with a condition of disorder, unpredictability, or uncertainty. The word and idea are utilised in a wide range of areas, from classical thermodynamics, where it was originally identified, through statistical physics' microscopic description of nature, to information theory's principles. It has a wide range of applications in chemistry and physics, biological systems and their relationships to life, cosmology, economics, sociology, weather science, climate change, and information systems, including telecommunications. It's a state function, after all. It is determined by the condition of the system rather than the path taken. It is denoted by the letter S, although in the normal state, it is denoted by the letter$\;S^\circ$. J/Kmol is the SI unit for it. Entropy is a scalable property, meaning it grows in proportion to the size or scope of a system. Note that in an isolated system, the greater the disorder, the higher the entropy. Entropy increases when reactants break down into a larger number of products during chemical processes. A system with more unpredictability has a higher temperature than one with a lower temperature. It is obvious from these instances that when regularity decreases, entropy increases.
Entropy is a state function since it depends not only on the start and end states, but also on the entropy change between two states, which is integrating tiny entropy change along a reversible route.

Note:
Thermodynamically, all naturally occurring spontaneous reactions are irreversible.
Thermodynamically, complete heat transmission into work is not possible without wasting a certain amount of energy.
The universe's entropy is always rising.
The change in total entropy is always positive. A system's entropy plus the entropy of its surroundings will be larger than zero.