1. What is entropy? What is its significance for engineering devices and processes?
Solution
Entropy is a thermodynamic quantity representing the unavailability of a system's thermal
energy for conversion into mechanical work, often interpreted as the degree of disorder or
randomness in the system. The entropy of a substance is real physical quantity and is a definite
function of the state of the body like pressure, temperature, volume of internal energy.
Significance- the significance of entropy revolves around the stability of a system/reaction. the
higher the entropy, the more unstable the system/reaction. from the third law of thermodynamics
we know that the entropy of a crystalline solid is zero at the absolute temperature (0 K). thus this
is the most stable form of a substance. An increase in entropy implies a transition from on
ordered to a less ordered state of affair.