• R. P. PRAJAPATI
• D.R. Tiwari

As we know that complexes formation tendency is depends on nature of central metal ions and ligands. Both chemical species responsible for formulae and stability constant during the formation of complexes and ratio of both chemical species shown the composition of formulae and stability constant. Stability constant in solution of both chemical species shown the thermodynamic stability or kinetic stability of complexes. For this purpose, spectrophotometric used to determine the formulae and stability constant of complexes. Spectrophotometric out of which one is the method of continuous variation, which was designed by Job, hence called as job’s method. The absorbance of Copper –EDTA Complex, Cobalt –Hydrazine complex, and Zinc – EDTA Complex, determined for each of the above complexes were measured by Systronics UV- Visible Spectrophotometer. In practice an equilibrium solution of the two reactants are mixed in varying ratios and the absorbance of each mixture is determined at a selective wavelength. The absorbance is plotted against the mole fraction of the metal or ligand in the flasks. The resulting curves are called as jobs plots. The ratios that corresponds to the mole fractions the components in the complex will attain a maximum absorbance value. The positions of the maximum indicate the ligand metal ratio of the complex in solution. The value of maxima was the value of ‘n’ in the formula of the complex, thus one can determine the formula of the complex.

Formulae and stability constants, mole fraction, UV- Visible Spectrophotometer, ligands, central metal ions.

"Spectrophotometric study of complexes to determine the formulae and stability constant", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.13, Issue 2, page no.a483-a489, February-2026, Available :http://www.jetir.org/papers/JETIR2602066.pdf

"Spectrophotometric study of complexes to determine the formulae and stability constant", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.13, Issue 2, page no. ppa483-a489, February-2026, Available at : http://www.jetir.org/papers/JETIR2602066.pdf