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MS FARZANA MEHBOOBD.A.NEELUM HIGH SCHOOL

Instructional Lesson

on

ELECTROCHEMISTRY

Overview

• Electrochemistry

introduction

• Cell &Batteries

Electrolysis & its Application

ELECTROCHEMISTRY

FARADAY

From Wikipedia

FOUNDERS

DANIELL

ELECTROCHEMISTRY

ELECTRON TRANSFER REACTIONS

ELECTRIC CURRENT

involves

cause generateOR

Branch of Chemistry

is a

Redox reactions

also called

Redox reactions

Electrochemical reactions

Spontaneous

Galvanic cells

Batteries

Non spontaneous

Electrolytic cells

CONCEPT MAPREDOX REACTIONS

• The loss of electrons is called oxidation,

• The gain of electrons is reduction.

REDUCING OXIDIZING AGENT AGENT

• A redox reaction can be divided into two Half Reactions:

• an oxidation reaction • a reduction reaction.

OIL, Oxidation Is Loss,RIG, Reduction Is Gain

“ An OIL RIG"

This can be easily remembered through:

9

Oxidation-Reduction ReactionsOXIDATION = loss of electrons

Examples:

Na Na+ + e-

Al Al3+ + 3e-

S2- S + 2e-

OXIDATION = increasing the oxidation number (more positive)Example:

NO NO2 -2+2 -2+4

change = +2

+2 to +4 : N is oxidized

Oxid. Nos:

Examples:

Na Na+ + e-

Al Al3+ + 3e-

S2- S + 2e-

OXIDATION-REDUCTION REACTIONS

OXIDATION-REDUCTION REACTIONS

Direct Redox ReactionOxidizing and reducing

agents in direct contact.

Cu(s) + 2 Ag+(aq) ---> Cu2+(aq) + 2 Ag(s)

OXIDATION-REDUCTION REACTIONS

OXIDATION-REDUCTION REACTIONS

Indirect Redox Reaction

A battery

Oxidizing and reducing agents are not in direct

contact

Why do reduction-oxidation reactions occur?

It is all about energy. 

Reduction and = an analogous flow oxidation of electrons.

The energy of a chemical system drives the charges to move.

Galvanic cellsElectrochemical cells

Chemical energyElectrical energy

Daniell cell

Redox reaction take place

Voltaic cells1.1 voltage

intoused to convert

in simplest form

has

CONCEPT MAP OF GALVANIC CELL

are

also called

in which

Parts of a Galvanic cell

Two electrodes of different metals

Electrolyte

An electrical wire A salt bridge

Cathode compartment

• The compartment in which reduction occurs. 

• The reaction at the cathode: Cu2+ (aq)  +  2e- --->  Cu (s)

Cathode electrodeCu

Electrolyte (CuSO4)

Anode compartment

The compartment in which oxidation occurs 

The reaction at the anode :

• Zn (s)  --->Zn2+ (aq)  +  2e-

anode electrodeZn

Electrolyte (ZnSO4)

Story ofAn Ox

&Red Cat

Story ofAn Ox

Red Cat

AND

ANode OXidation

REDuction CAThode

ANODE NEGATIVE DANIEL

Electrolysis

Electro

electricity

and lysisBreak

apart

WHAT IS ELECTROLYSIS

TYPES OF ELECTROLYTE

GENERAL TERMS USED IN ELECTROLYSIS

Electrolytic cell It has three component parts:

1. An electrolyte 2. Two electrodes

(a cathode and an anode).

3. A battery

VIDEO OF ELECTROLYSIS

ELECTROPLATING

EXTRACTION OF

METALS

ANODIZING

ELCTROREFINING

PREPARATION OF ALKALI & CHLORINE

GASIndustrialApplication of electrolysis

Electrolysis of molten Alumina

VIDEO

26

cathode:Au+(aq) +e-→Au

anode:Au→Au+(aq) +e-

external power source

Au

Au+(aq) Au+(aq)

Au

external power source

Gold plating

COPPER REFININGVIDEO

SUMMARY

Concept Map

The End

PRESENTER

MS FARZANA MEHBOOB

D.A.Neelum High School