An unknown cadmium (II) solution was analyzed polarographically by the method of standard additions. A 25.00 mL sample of the unknown solution produced a diffusion current of 1.86 µA. Following addition of 5.00 mL aliquot of 2.12 x 10-3 M Cd²+ standard solution to the unknown solution, a diffusion current of a 5.27 µA was produced. Calculate the concentration of Cd²+ in the unknown solution.

An unknown cadmium (II) solution was analyzed polarographically by the method of standard additions. A 25.00 mL sample of the unknown solution produced a diffusion current of 1.86 µA. Following addition of 5.00 mL aliquot of 2.12 x 10-3 M Cd²+ standard solution to the unknown solution, a diffusion current of a 5.27 µA was produced. Calculate the concentration of Cd²+ in the unknown solution.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter23: Potentiometry

Section: Chapter Questions

Problem 23.7QAP

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An unknown cadmium(II) solution was analyzed polarographically by the method of standard additions. A 25.00-mL sample of the unknown solution produced a diffusion current of 1.86 mA. Following addition of a 5.00-mL aliquot of 2.12x10^23 M Cd2+ standard solution to the unknown solution, a diffusion current of 5.27 mA was produced. Calculate the concentration of Cd2+ in the unknown solution.
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Discuss the advantages, disadvantages, and limitations of the technique of cyclic voltammetry in both qualitative and quantitative measurements.