Calculating Entropy Changes for Reactions
?S?universe = ?S?system + ?S?surroundings
?S?system = ? S?(products) - ? S?(reactants)
?S?surroundings = qsurroundings/T = - ?Hsystem/T
First Law of Thermodynamics:
The total energy of the universe is constant
Second Law of Thermodynamics:
The total entropy of the universe is continually increasing
Third Law of Thermodynamics
The entropy of a pure perfect crystalline solid at 0K is 0.