1.1 What is Chemistry?

http://www.ck12.org Chapter 23. Electrochemistry

23.1 Electrochemical Cells

Lesson Objectives

• Use the activity series to predict whether a given oxidation-reduction reaction will occur spontaneously.


• Describe the components and function of a galvanic cell.


• Describe how power is produced by lead-acid batteries, dry cell batteries, and fuel cells.

Lesson Vocabulary

• activity series: A ranking of various metals on their ability to lose electrons.


• galvanic cell: A cell in which two solutions are connected by a wire in order to facilitate the flow of electrons
  and generate an electric current.


• battery: A cell which employs oxidation-reduction reactions to generate a flow of electrons and supply
  electricity.


• lead-acid battery: A battery with two poles, one of lead and one of lead oxide, submerged in sulfuric acid
  and separated by a barrier permeable to ions and water; typically used in cars.


• dry cell battery: Contains a paste (often a mixture of ammonium chloride and manganese dioxide) that acts
  as the positive electrode.


• fuel cell: A cell that is able to produce an electric current directly from a chemical reaction; fuel cells
  commonly operate on the platinum catalyzed reaction between hydrogen and oxygen gases to be used to
  power vehicles.

Check Your Understanding

Recalling Prior Knowledge

• Write half reactions for the following redox process:

2 Na + Cl 2 →2 NaCl

What is being oxidized, and what is being reduced?

Introduction

Electrochemistry is the study of chemical processes that occur at the interface between an electron conductor, such
as a wire, and a solution of electrolytes, which is often simply an ionic substance dissolved in water. Electrochemical
processes involve a transfer of electrons between the wire and the solution. These reactions can be used to create
electrical power, to purify metals, and to carry out a number of useful chemical transformations.