Polarography and Amperometric titrations:
We will begin our discussion along with a classical polarogram and then the dropping mercury electrode (DME). After discussing in detail the benefits of a DME we will continue our discussions on limiting and migration current, followed through diffusion and residual current. The factors affecting residual current are then elaborates. This is followed through the discussion on half wave potential, E1/2 and effect on complexing agents on it. A determination of n and reversibility are discussed taking the log plot of Cd(II) in 1 M KCl. The Discussion of kinetic currents, adsorption waves, catalytic currents, polarographic maxima and maximum suppressors are then done. Qualitative as well as quantitative polarographic analysis involving calibration plot, internal standard method and method of standard further are discussed. The discussion on polarography is concluded along with the instrument included in polarographic analysis. After that we discuss amperometric titrations where we begin with the advantages of amperometry followed through a few examples of amperometric titrations.
Objectives
you should be able after studying this unit:
- discuss polarography,
- define the details of a dropping mercury electrode,
- define the limiting and migration currents,
- define the diffusion and residual currents,
- define the factors affecting the diffusion current,
- provide the details of the polarographic equation ,
- define the E1/2 and effect of complexing agents,
- define the estimation of n-values and reversibility,
- define the currents other than the diffusion current,
- define the polarographic maxima and maximum suppressors,
- define the qualitative and quantitative polarographic analysis,
- define the instrument, and
- define the details of amperometric titrations