Corrosion inhibition of Copper by the extracts of Tephrosia Purpuria in H₂SO₄ media was studied. Mass loss studies have been carried out at room temperature. The effects of temperature and concentration on the inhibition performance of the extracts have also studied. The results are discussed.
 

The study has been focused on investigations of physico-chemicals characteristics and heavy metal contents in water samples. The water samples were collected from different sites in and around Dhule District (M.S.). The physico-chemical study revealed that pH, EC, Total alkalinity and heavy metals were found in variable amounts in different seasons.
 

The composition and stability of Rhodium-Eriochrome cyanine R (abbreviated as ECR) has been studied. The pink colored chelate has maximum wavelength at 530 nm and a composition of 1:2 (metal: chelating). The chelate is stable between pH 2 to 5. The values of Log K ( K= Stability constant ) as calculated by Dey and Coworkers, Job's method of Continuous Variation and Mole Ratio method using absorbance data are10.1, 9.9 and 10.2 respectively at pH 4 and at 25^oC. The colored complex confirms to Beer's law over the rhodium concentration of 0.60 to 9.8 ppm.

Kinetics and Mechanism of oxidation of DL-Aspartic Acid by Chromic Acid in presence of Hydrochloric Acid has been carried out at 29^oC. The reaction is first order with respect to (DL-Aspartic Acid) & (Chromic Acid) and the total order is two. The order of reaction with respect to [H+] ion is also one. Ostwald isolation method is used for study of rate of reaction. The probable products are acetaldehyde, CO₂ & ammonia. Mechanism involving C-C fission has been suggested. The rate of reaction increases with increase in the Hydrochloric Acid concentration in the system. The rate constant has been computed by first order reaction. The pH value, Catalytic constant and temperature coefficient have also been determined for all the runs. On the basis of experimental findings, the proposed rate expression is. -d [Cr(VI)] = k [ Cr (VI)] [DL-Aspartic Acid] [H⁺] dt

Various acoustic parameters such as isentropic compressibility (b_s), intermolecular free length (L_f), apparent molar volume (f), apparent molar compressibility (f_k), molar compressibility (w), molar sound velocity (R),acoustic impedance (z) of Na₂SO₄ in 10%, 20% and 30% methanol+water at303.15 K have been determined from ultrasonic velocity (V), density (r) and relative viscosity (h_r) of the solution. These parameters are related with the molar concentration of the solution and reflects distortion of the structure of the solvent (i.e., Propan-2-ol+water) when the solute is added to it.

The reactions of hexabutylditin with monofunctional bidentate Schiff bases in 1:2 molar ratio were studied in the medium of anhydrous benzene. Complexes of the type R₃Sn-SB (where R= -C₄H₉ and SB is Schiff base) have been synthesized. All reactions were not so facile and tin-tin bond was cleaved in preference to the tin-carbon bond. The resulting derivatives were obtained in the form of yellow liquids while some were found to be solids. They are soluble in common organic solvents and are highly sensitive to the atmospheric moisture. These complexes were found to be monomers. In these complexes, the tin atom probably attains coordination number of five and have trigonal bipyramidal structure.

Proteins can be separated by different electrophorotic methods like, electrophoresis using paper, thin layer and gels, etc. In the present study, we use the method of "Gel Electrophoresis" for the separation of proteins. First the different protein samples (Limulin, C-reactive protein, P-Small, P-large) and the gels are prepared. These different protein samples are loaded on the gel, and they get separated based on their molecular weights. Finally the bands are identified by comparing with the molecular weights of the Standard proteins.
Key words: Proteins, Electrophoresis, Gels, Molecular weight.

The reactions of hexaphenyldilead with oxygen and nitrogen donor ligands like 8-hydroxyquinoline, ethylcarbamate and triphenyl phosphine oxide were studied in the medium of anhydrous benzene. Complexes of the type R₃Pb-L and [R₃Pb]₂­2L' (where L= 8-hydroxyquinoline, ethylcarbamate and L'= Triphenylphosphine oxide and R= -C₆H₅) have been synthesized. All the reactions were found to be quite facile. It has been observed that lead-lead bond was cleaved in preference to the lead­carbon bond. The resulting derivatives of lead (IV) were isolated in the form of yellow or black solids. They were found to be insoluble in common organic solvents. In these complexes, the lead atom is probably pentacoordinated and the structure is trigonal bipyramidal configuration.