Question

First, distinguish clearly between voltammetry and polarography, second state one very attractive feature of polarography, third arrange the following in increasing order of sensitivity: stripping analysis, sampled current voltammetry, and square wave voltammetry, and finally state why the last voltammetric method in your order is the most sensitive.

Answer 1

1.The voltammetry is the technique used in electrochemistry in which the time dependent potential is applied to an electrochemical cell.

In this technique the the current flowing through the cell is measured as a function of that potential.

Whereas in the polarography techinque the current which flow through the cell is measured as a function of potential of the working electrode.

2.The main attractive featire of polarography is that the polarography is a particular type of voltammetry where the working microelectrode used is the dropping mercury electrode.

3.The sensitivity order is as follows:-

Square wave voltammetry>stripping analysis>current sampled voltammetry.

The square wave voltammetry is sensitive because it is used for the analysis at the parts per billion and parts per trillion levels.

The sensitivity of square wave voltammetry allows the kinetic measurements in the very dilute solutions also.