This paper is a continuation of a previous paper of the author which explains how a chemical analysis of theratio by weight of O-16 and H-1 in plain water (the presence of different isotopes of O and H would not affect the experiment) could decide if the hypothesis of mass-energy equivalence based on E=mc2 is verified or refuted; a refutation would mean a full revival of the classical law of conservation of mass without any need of mass-energy equivalence consideration. The proposed experiment is by electrolysis of water as an aqueous solution of potassium sulfate. Oxygen produced at the anode is trapped while the hydrogen produced at the cathode are allowed to escape freely. With three weighing with an analytical balance in vacuum, the ratio of O/H could be determined with a high degree of accuracy. The mass-energy equivalence principle accepted in present day physics may be said to be the foundational assumption in present day physics. If it fails, then current high energy physics would collapse. This includes the Standard Model of particle physics widely promulgated by CERN and much of all modern physics. The irony is that mass-energy equivalence and the equation E=mc2 have never been experimentally verified. This has been explained in detail in the author’s other paper.