Thermodynamics of complex formation: nickel—caprolactam system

Polarographic techniques have been used to investigate the complexing reactions in aqueous solution between ε-caprolactam and nickel ion. The coordination number and stability constants of the complex have been determined polarographically. The method of Ringbom and Eriksson using cadmium as indicator ion was used on the basis of reversible and irreversible character of electrode reactions at dropping mercury electrode. The stability constants obtained at various temperatures were used to calculate various thermodynamic functions by graphical method.