Question

Please help explain the relationship between spontaneity, irreversibility, and entropy change. How do these terms relate, as well as how to predict one given another's condition.

Answer 1

In chemistry, a spontaneous processes or spontaneity is one that occurs without the addition of external energy. A spontaneous process may take place quickly or slowly, because spontaneity is not related to kinetics or reaction rate.

2)An irreversible process is a process that cannot return both the system and the surroundings to their original conditions. That is, the system and the surroundings would not return to their original conditions if the process was reversed.

3)entropy change - For a closed thermodynamic system, a quantitative measure of the amount of thermal energy not available to do work. Or- A measure of the disorder or randomness in a closed system.

Relation between them

spontaneous process is always irreversible in nature and entropy of universe always increase in case of spontaneous reaction.