Cyclic Voltammetry

Cyclic voltammetry (CV) is an experimental electrochemistry technique used to determine the reversibility of oxidation-reduction reactions in addition to other electrochemical properties of an analyte. A CV cell employs a three-electrode setup consisting of a reference electrode, working electrode, and a counter electrode dissolved in an electrolyte solution into which the compound of interest is dissolved.

Figure 1: Setup of a CV experiment. WE = working electrode, RE = reference electrode, and CE = counter electrode.

Throughout the experiment, a current is applied to and linearly increased at the inert working electrode. The counter electrode completes the circuit resulting in current flow through the electrolyte solution allowing the oxidation-reduction reaction to occur at the working electrode. The E_cell of the reaction is measured in comparison to the reference electrode and plotted versus the current. The resulting graph is called a voltammogram.

Figure 1: Voltammogram

The characteristic duck shape of a voltammogram is derived from the switching of negative scanning (cathodically) to positive scanning (anodically) at the working electrode as the initial reaction reaches completion. Various portions of the graph can then be analyzed to determine the K_eq of the reaction.

If a cyclic voltammetry experiment is carried out with Fe (E_red = -0.45 V) and Ag (E_red = +0.80 V) what initial voltage must be supplied to the circuit in order for negative scanning to occur?

Cyclic voltammetry (CV) is an experimental electrochemistry technique used to determine the reversibility of oxidation-reduction reactions in addition to other electrochemical properties of an analyte. A CV cell employs a three-electrode setup consisting of a reference electrode, working electrode, and a counter electrode dissolved in an electrolyte solution into which the compound of interest is dissolved.

Figure 1: Setup of a CV experiment. WE = working electrode, RE = reference electrode, and CE = counter electrode.

Throughout the experiment, a current is applied to and linearly increased at the inert working electrode. The counter electrode completes the circuit resulting in current flow through the electrolyte solution allowing the oxidation-reduction reaction to occur at the working electrode. The E_cell of the reaction is measured in comparison to the reference electrode and plotted versus the current. The resulting graph is called a voltammogram.

Figure 1: Voltammogram

The characteristic duck shape of a voltammogram is derived from the switching of negative scanning (cathodically) to positive scanning (anodically) at the working electrode as the initial reaction reaches completion. Various portions of the graph can then be analyzed to determine the K_eq of the reaction.

If a cell generates a voltage difference of +6V when the working electrode and counter electrode are placed 2 cm apart what force will a 2.38 x 10^-11 C charge experience?

Cyclic voltammetry (CV) is an experimental electrochemistry technique used to determine the reversibility of oxidation-reduction reactions in addition to other electrochemical properties of an analyte. A CV cell employs a three-electrode setup consisting of a reference electrode, working electrode, and a counter electrode dissolved in an electrolyte solution into which the compound of interest is dissolved.

Figure 1: Setup of a CV experiment. WE = working electrode, RE = reference electrode, and CE = counter electrode.

Throughout the experiment, a current is applied to and linearly increased at the inert working electrode. The counter electrode completes the circuit resulting in current flow through the electrolyte solution allowing the oxidation-reduction reaction to occur at the working electrode. The E_cell of the reaction is measured in comparison to the reference electrode and plotted versus the current. The resulting graph is called a voltammogram.

Figure 1: Voltammogram

The characteristic duck shape of a voltammogram is derived from the switching of negative scanning (cathodically) to positive scanning (anodically) at the working electrode as the initial reaction reaches completion. Various portions of the graph can then be analyzed to determine the K_eq of the reaction.

Which of the following will occur as the cyclic voltammetry experiment progresses?

Cyclic voltammetry (CV) is an experimental electrochemistry technique used to determine the reversibility of oxidation-reduction reactions in addition to other electrochemical properties of an analyte. A CV cell employs a three-electrode setup consisting of a reference electrode, working electrode, and a counter electrode dissolved in an electrolyte solution into which the compound of interest is dissolved.

Figure 1: Setup of a CV experiment. WE = working electrode, RE = reference electrode, and CE = counter electrode.

Throughout the experiment, a current is applied to and linearly increased at the inert working electrode. The counter electrode completes the circuit resulting in current flow through the electrolyte solution allowing the oxidation-reduction reaction to occur at the working electrode. The E_cell of the reaction is measured in comparison to the reference electrode and plotted versus the current. The resulting graph is called a voltammogram.

Figure 1: Voltammogram

The characteristic duck shape of a voltammogram is derived from the switching of negative scanning (cathodically) to positive scanning (anodically) at the working electrode as the initial reaction reaches completion. Various portions of the graph can then be analyzed to determine the K_eq of the reaction.

As the reaction progresses the dissolved analyte ions in the electrolyte solution are depleted. What effect does this have on the current produced by the power source if the voltage remains the same?