ENERGETICS OF CU (II)-CATALYSED OXIDATION OF MERCAPTOSUCCINIC ACID BY METHYLENE BLUE IN ABSENCE AND IN PRESENCE OF PYRAZOLONE IN ACIDIC MEDIUM.

The reaction between mercaptosuccinic acid (TMA) and methylene blue (MB) was investigated in acidic mediumusing Cu (II) as catalyst. Two moles of substrate are oxidized by one mole of MB forming the corresponding disulphide anddihydromethylene blue. The order in MB is zero while order in TMA is unity. The rate shows a maximum on varying [H+]whereas it increases linearly on increasing [Cu (II)]. Electrolytes exert a diverse influence, which is attributed toenvironmental effect. The rate increases on increasing the dielectric constant of the medium but it remains unaffected onadding externally the disulphide and leucobase to the system. It is known that Zn (II)-pyrazole complex acts as a model forthe enzyme, liver alcohol dehydrogenase (LADH) which regulates the function of liver22.3-Methyl-1 phenyl-2-pryazoline-5-one (Pyrazolone) was also added to the system in a bid to investigate the effect of simultaneous ligation of catalyst on therate and pyrazolone was found to retard the reaction