Abstract

Usha Maroo, Pradeep Maroo, R. S. Chauhan and D. N. Purohit

3-Hydroxy-3-o-tolyl-1-p-chlorophenyltriazene has been used for the spectrophotometry determination of Pb(ll). Lead forms a 1:2 (Pb:R) yellow complex with the reagent. The complex shows maximum absorbance at 395 nm. (ε = 7,000) in the pH range 7.0-7.5. Absorbance measurements were made at 400 nm. Values of molar absorptivity. Sandell's sensitivity, stability constant (log β) and free energy of formation were found to be 7,000 1.Mole-1 cm-1, 29.6 ng/cm2, 9.08 and 12.465 k.cal/mole respectively. Beer's law is obeyed in the entire concentration range studied i.e. 1.0 x 10-5 M to 7.0 x 10-5 M. It was possible to determine lead (10.36 mg) in presence of two fold molar excess of twenty cations and anions.

Hydroxy; chlorophenyltriazene; spectrophotometry anions

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