MS FARZANA MEHBOOB D.A.NEELUM HIGH SCHOOL Instructional Lesson on ELECTROCHEMISTRY MS FARZANA MEHBOOB D.A.NEELUM HIGH SCHOOL

Overview Electrochemistry introduction Cell &Batteries Electrolysis & its Application

ELECTROCHEMISTRY FARADAY DANIELL F O U N D E R S From Wikipedia

ELECTRON TRANSFER REACTIONS ELECTROCHEMISTRY ELECTRON TRANSFER REACTIONS ELECTRIC CURRENT is a Branch of Chemistry involves also called Redox reactions generate cause OR

Electrochemical reactions CONCEPT MAP REDOX REACTIONS Redox reactions Electrochemical reactions Spontaneous Galvanic cells Batteries Non spontaneous Electrolytic cells

The loss of electrons is called oxidation, A redox reaction can be divided into two Half Reactions: an oxidation reaction a reduction reaction. The loss of electrons is called oxidation, The gain of electrons is reduction. REDUCING OXIDIZING AGENT AGENT

OIL, Oxidation Is Loss, RIG, Reduction Is Gain This can be easily remembered through: OIL, Oxidation Is Loss, RIG, Reduction Is Gain “ An OIL RIG"

Oxidation-Reduction Reactions OXIDATION = loss of electrons Examples: Examples: Na  Na+ + e- Al  Al3+ + 3e- S2-  S + 2e- Na  Na+ + e- Al  Al3+ + 3e- S2-  S + 2e- OXIDATION = increasing the oxidation number (more positive) Example: NO  NO2 Oxid. Nos: +2 -2 +4 -2 change = +2 +2 to +4 : N is oxidized

OXIDATION-REDUCTION REACTIONS Direct Redox Reaction Oxidizing and reducing agents in direct contact. Cu(s) + 2 Ag+(aq) ---> Cu2+(aq) + 2 Ag(s)

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. E

CONCEPT MAP OF GALVANIC CELL Galvanic cells Electrochemical cells Chemical energy Electrical energy Daniell cell Redox reaction take place Voltaic cells 1.1 voltage used to convert into are in simplest form in which has also called

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 electrode Cu Electrolyte (CuSO4)

Anode compartment The compartment in which oxidation occurs anode electrode Zn Electrolyte (ZnSO4) The compartment in which oxidation occurs  The reaction at the anode : Zn (s)  --->Zn2+ (aq)  +  2e-

Story of An Ox & Red Cat

Story of An Ox Red Cat AND ANODE NEGATIVE DANIEL ANode OXidation REDuction CAThode

electricity Break apart Electrolysis Electro lysis WHAT IS ELECTROLYSIS Electrolysis Latin word Electro electricity and lysis Break apart through

TYPES OF ELECTROLYTE

GENERAL TERMS USED IN ELECTROLYSIS Electrolytic cell It has three component parts: An electrolyte Two electrodes (a cathode and an anode). A battery

VIDEO OF ELECTROLYSIS

PREPARATION OF ALKALI & CHLORINE GAS ELECTROPLATING EXTRACTION OF METALS ANODIZING ELCTROREFINING PREPARATION OF ALKALI & CHLORINE GAS Industrial Application of electrolysis

Electrolysis of molten Alumina

VIDEO

Gold plating cathode: Au+(aq) +e-→Au anode: Au→Au+(aq) +e- external power source external power source Au Au Au+(aq) Au+(aq) cathode: Au+(aq) +e-→Au anode: Au→Au+(aq) +e-

VIDEO COPPER REFINING

30/09/99 SUMMARY

Concept Map

30/09/99 The End

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