PPT: Electrochemistry | Chemistry for JEE Main & Advanced PDF Download

 Page 1


E l e c t r o
c h e m i s t r y
E l e c t r o
c h e m i s t r y
 Chemistry
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E l e c t r o
c h e m i s t r y
E l e c t r o
c h e m i s t r y
 Chemistry
Electrochemistry is the study of production of electricity from
energy released during spontaneous chemical reactions and the
use of electrical energy to bring about non-spontaneous chemical
transformations.
Introduction
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E l e c t r o
c h e m i s t r y
E l e c t r o
c h e m i s t r y
 Chemistry
Electrochemistry is the study of production of electricity from
energy released during spontaneous chemical reactions and the
use of electrical energy to bring about non-spontaneous chemical
transformations.
Introduction
What is reduced is the oxidizing agent.
H ? oxidizes Zn by taking electrons from it.
What is oxidized is the reducing agent.
Zn reduces H ? by giving it electrons.
Oxidation and Reduction
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E l e c t r o
c h e m i s t r y
E l e c t r o
c h e m i s t r y
 Chemistry
Electrochemistry is the study of production of electricity from
energy released during spontaneous chemical reactions and the
use of electrical energy to bring about non-spontaneous chemical
transformations.
Introduction
What is reduced is the oxidizing agent.
H ? oxidizes Zn by taking electrons from it.
What is oxidized is the reducing agent.
Zn reduces H ? by giving it electrons.
Oxidation and Reduction
Electrochemical Cells
Page 5


E l e c t r o
c h e m i s t r y
E l e c t r o
c h e m i s t r y
 Chemistry
Electrochemistry is the study of production of electricity from
energy released during spontaneous chemical reactions and the
use of electrical energy to bring about non-spontaneous chemical
transformations.
Introduction
What is reduced is the oxidizing agent.
H ? oxidizes Zn by taking electrons from it.
What is oxidized is the reducing agent.
Zn reduces H ? by giving it electrons.
Oxidation and Reduction
Electrochemical Cells
The cell that converts chemical energy to electrical energy is called
Daniell's cell. It has an electrical potential equal to 1.1 V when the
concentration of Zn² ? and Cu² ? ions is unity (1 mol dm ?³). Such a device is
called a galvanic or a voltaic cell.
If an external opposite potential is applied in the galvanic cell [Fig. 3.2(a)]
and increased slowly, we find that the reaction continues to take place
till the opposing voltage reaches the value 1.1 V when, the reaction
stops altogether and no current flows through the cell.
Any further increase in the external potential again starts the reaction
but in the opposite direction. It now functions as an electrolytic cell, a
device for using electrical energy to carry non-spontaneous chemical
reactions.
Zn(s) + Cu² ?(aq) ? Zn² ?(aq) + Cu(s)