Electrochemistry An Introduction

I AIMS To understand the term electrochemistry. To learn to identify the components of an eiectrochemicai (gaivanic) ceii. 

Our lives would be very different without batteries. We would have to crank the engines in our cars by hand, wind our watches, and buy very long extension cords if we wanted to listen to a radio on a picnic. Indeed, our society sometimes seems to run on batteries. In this section and the next, we will find out how these important devices produce electrical energy. 

A battery uses the energy from an oxidation-reduction reaction to produce an electric current. This is an important illustration of electrochemistry, the study of the interchange of chemical and electrical energy. Electrochemistry involves two types of processes  

The production of an electric current from a chemical (oxidation-reduction) reaction 

To understand how a redox reaction can be used to generate a current, let s reconsider the aqueous reaction between Mn04 and Fe that we worked with in Example 17.5. We can break this redox reaction into the following half-reactions  

What is the key to getting useful energy from an oxidation-reduction reaction  

EXERCISE 18.4 Copper metal reacts with nitric acid, HNOziaq), to give aqueous copper(ll) nitrate, water, and nitrogen monoxide gas as products. Write and balance the equation for this reaction. 

The energy involved in a chemicai reaction is customariiy not shown in the baianced equation, in the reaction of Mn04 with Fe, energy is released that can be used to do useful work. 

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H. Rickert, Solid State Electrochemistry An Introduction, Springer-Verlag, Berlin, 1982. 

Lund, H., and M. M. Baizer, Organic Electrochemistry An Introduction and Guide, Marcel Dekker, New York, 1991. 

M. M. Baizer and H. Lund, Organic Electrochemistry an Introduction and a Guide , Dekker, New York, 1983. 

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