work stimulates uniform motion of atoms in the surroundings and so does not
change their entropy.
The thermodynamic definition of entropy is based on the expression
dS = [3.1]
where qrev is the heat supplied reversibly. For a measurable change between two states
i and f this expression integrates to
ΔS =
f
i
(3.2)
That is, to calculate the difference in entropy between any two states of a system, we
find a reversible path between them, and integrate the energy supplied as heat at each
stage of the path divided by the temperature at which heating occurs