Job's plot of complex Au(III)-azo ligand at PH 5 Linear range 1.0 mL of 1.0  10 -3 M 2-(4-antipyrineazo)-4-nitroaniline was pipetted into each of ten 10-mL volumetric flask containing 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 mL of Au (III) (1.0 10 3 M ). The solutions were made up to 10 mL by phosphate buffer solution of pH (5). After 60 minutes, the absorbance of the solutions were measured at 610 nm and plotted against Au (III) concentration in μgmL -1 (Figures 9 and 10).

Context in source publication

Context 1

... method of continuous variation and molar ratio was applied as described by Yoe and Jones (1944). Keeping the sum of the molar concentration of Au(III) and 2-(4-antipyrineazo)-4-nitroaniline constant, the ratio of both Au (III) and 2-(4-antipyrineazo)-4-nitroaniline varied (see experimental section) and the absorbance of the resultant mixtures were recorded at 610nm and PH 5 The maximum absorbance corresponds to the stoichiometric ratio, this was found at 1:1(Au (III) : 2-(4-antipyrineazo)-4-nitroaniline) as shown in Figure 8, below. ...