Entropy

          Entropy is the second law of thermodynamics that deal with the randomness and disorder.The law states that all systems will spontaneously increase in entropy over time. Entropy measures the randomness of objects as well as energy using the symbol S. Some examples of the usages of entropy includes: change of state (from ice to water), energy form, and number of particles. REDOX reaction could be used to test whether a reaction fits into the law of thermodynamics or not:
C3H4O3 + NADH + H ---> C2H5OH + CO2 +NAD