Introduction

Electrochemistry is defined as the branch of chemistry which deals with the relationship between chemical energy and electrical energy taking place in a redo reaction and inter conversion of one form of energy into another. A cell or a battery converts chemical energy into electrical energy which can be used to operate various equipments. The reverse process is also possible in which we can make non–spontaneous processes occur by supplying external energy in form of electrical energy. These inter conversions are carried out in equipments called “Electrochemical Cells”. Electrochemical Cells are of two types:

1. Galvanic Cells: Converts chemical energy into electrical energy

2. Electrolytic Cells: Converts electrical energy into chemical energy

 Hence in this chapter we will discuss these two inter-conversions.

 We will explore the concepts of electrochemistry in more details under following subtopics:

• Conductors and Non Conductors
• Galvanic cell
• Electrode Potential: WHAT IS ELECTRODE POTENTIAL?
• Measurement of the standard electrode potential (E^o): Reference Electrode
• Cell potential / E.m.f. of cell
• Electrochemical Series
• Applications of Electrochemical Series
• Spontaneity of a reaction (Relation between Emf and Gibb’s free energy)
• EFFECT OF CONCENTRATION ON ELECTRODE POTENTIAL (NERNST EQUATION):
• Electrolytic Cell
• Conductance of Solutions/ electrolytic conductance
• Effect of concentration on Conductance
• Kohlrausch’s law.
• Faradays laws of electrolysis.
• Batteries: