12C03��Electrochemistry
Li-ion Battery
Electrochemistry
Electro + Chemistry
It deals with interconversions between Electrical and Chemical energy
12C03.1
Galvanic Cell and Cell Potential
Learning Objectives
Redox Reaction
Galvanic Cell
Electrode Potential
Cell Potential
12C03.1 Galvanic Cell and Cell Potential
12C03.1
CV 1
Redox Reaction
Redox Reactions
Reduction Reactions
Oxidation Reactions
Redox Reactions
Redox Reactions
Reduction Reactions
Oxidation Reactions
Redox Reactions
Redox Reactions
Reduction Reactions
Oxidation Reactions
Redox Reactions
`
Redox Reactions
Reduction Reactions
Oxidation Reactions
OIL RIG
Oxidation is loss of electron
Reduction is gain of electron
Redox Reactions
Oxidising and Reducing agents
Oxidation
Reduction
ConcepTest
Ready for Challenge
Pause the video
Time duration: 2 minutes
12C03.1
CV 2
Galvanic Cell
Electrochemical Cell
Electrochemical Cell
Galvanic or Voltaic Cell
Electrolytic Cell
Devices which are used to convert electrical energy into chemical energy and vice versa
Electrical energy is used to carry out a non-spontaneous redox reaction.
Chemical energy of a spontaneous redox reaction is converted into electrical energy.
Battery
Anode
Cathode
Salt Solution
Cathode
Anode
Salt Bridge
Galvanic Cell
LOAN
Left
Oxidation
Anode
Negative
Zn Anode
Cu Cathode
Voltmeter
Anode
Cathode
Salt Bridge
NaCl (aq)
Salt Bridge
Salt
Bridge
IUPAC representation of Galvanic Cell
Zn Anode
Cu Cathode
Voltmeter
Salt
Bridge
Galvanic Cell
12C03.1
CV 3
Electrode Potential
Electrode Potential
Potential difference developed between electrode and electrolyte.
According to IUPAC convention, standard reduction potentials are now called standard electrode potentials.
Standard Hydrogen Electrode
Determination of standard electrode potential of metals
Standard metal electrode
Metal rod
Electrochemical Series
Elements | Electrode Reaction | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
Oxidising
Nature
Reducing
Nature
Selection of oxidising and reducing agents
| | |
| | |
| | |
| | |
| | |
| | |
Reactivity of Metal
| | |
| | |
| | |
| | |
| | |
| | |
ConcepTest
Ready for Challenge
Pause the video
Time duration: 2 minutes
12C03.1
PSV 1
12C03.1
CV 4
Cell Potential
Cell Potential
Zn Anode
Cu Cathode
Voltmeter
Salt
Bridge
Galvanic Cell
Cell Potential
Zn Anode
Cu Cathode
Voltmeter
Salt
Bridge
Galvanic Cell
Gibbs free energy of Cell Reaction
Moles of electrons exchanged
Faradays constant (96500C/mol)
EMF of Cell
Equilibrium
Feasibility of Reaction
12C03.1
PSV 2
12C03.1
PSV 3
ConcepTest
Ready for Challenge
Pause the video
Time duration: 2 minutes
Summary
Reference Questions
NCERT In-text Questions: 3.1, 3.2, 3.3
NCERT Exercise Questions: 3.1, 3.2, 3.3, 3.6
Workbook Questions: 2, 4, 10, 11
12C03.1 Galvanic Cell and Cell Potential
12C03.2
Nernst Equation
Learning Objectives
Nernst Equation
Applications of Nernst Equation
12C03.2 Nernst Equation
12C03.2
CV 1
Nernst Equation
Nernst Equation
Anode
Cathode
Salt
Bridge
Galvanic Cell
Nernst Equation
Pause the video
Time duration: 4 minutes
Sol.
ConcepTest
Ready for Challenge
Pause the video
Time duration: 2 minutes
12C03.2
CV 2
Applications of Nernst Equation
Applications of Nernst Equation
Calculation of Equilibrium Constant
Pause the video
Time duration: 3 minutes
Internal electrode
Reference electrode
Ceramic junction
Test Solution
ConcepTest
Ready for Challenge
Pause the video
Time duration: 2 minutes
Sol.
Summary
Reference Questions
NCERT In-text Questions: 3.4, 3.5, 3.6
NCERT Exercise Questions: 3.5, 3.6, 3.17,
Workbook Questions: 11, 12, 17
12C03.2 Nernst Equation
12C03.3
Electrolytic Cell
Learning Objectives
Faradays Law of Electrolysis
Products of Electrolysis-I
Products of Electrolysis-II
12C03.3 Electrolytic Cell
12C03.3
CV 1
Faradays Laws of Electrolysis
Impure Cu electrode
Pure Cu electrode
DC source
Electrolytic Cell
The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.
Faradays First Law of Electrolysis
The amounts of different substances liberated by the same quantity of electricity passing through the electrolytic solution are proportional to their chemical equivalent weights.
Faradays Second Law of Electrolysis
12C03.3
PSV 1
12C03.3
CV 2
Products of Electrolysis-I
Products of Electrolysis
State of Electrolyte
Electrode
Concentration of Electrolyte
Products of Electrolysis
Pt cathode
DC source
Pt anode
Pt cathode
DC source
Pt anode
12C03.3
PSV 2
Sol.
12C03.3
CV 3
Products of Electrolysis-II
Pt cathode
DC source
Pt anode
Cu cathode
DC source
Cu anode
Pt cathode
DC source
Pt anode
Summary
Reference Questions
NCERT In-text Questions: 3.10, 3.11, 3.12
NCERT Exercise Questions: 3.12, 3.13, 3.14, 3.15, 3.16, 3.18
Workbook Questions: 7, 13, 19
12C03.3 Electrolytic Cell
12C03.4
Conductivity of Electrolytic Solution
Learning Objectives
Conductivity Cell
Measurement of Conductivity
Kohlrausch Law
12C03.4 Conductivity of Electrolytic Solution
12C03.4
CV 1
Conductivity Cell
Electrolytic Solution
Platinized Electrodes
Conductivity Cell
Conductance of Electrolytic solution
Nature of Electrolyte
Nature of Solvent
Size of Ions
Concentration of Electrolyte
Temperature
Conductance
Temperature
Conductance
Factors affecting Conductance of Electrolytic solution
Complete
dissociation
Partial
dissociation
A
+
+
-
-
Platinized Cathode
Platinized Anode
Electrolytic Solution
Conductivity Cell
Conductivity Cell
Classification of Substances on the basis of Conductivity
Substance
Conductor
Insulator
Semi conductor
ConcepTest
Ready for Challenge
Pause the video
Time duration: 3 minutes
Sol.
12C03.4
CV 2
Measurement of Conductivity
Conductivity
cell
Variable
resistance
Detector
Wheatstone bridge
Measurement of Conductivity
Molar Conductivity
Molar conductivity increases with dilution.
For strong electrolytes,
Strong Electrolyte
Weak Electrolyte
For weak electrolytes,
Ostwald Law of Dilution:
Equivalent Conductivity
ConcepTest
Ready for Challenge
Pause the video
Time duration: 3 minutes
Sol.
12C03.4
CV 3
Kohlrausch Law
The limiting molar conductivity of an electrolyte can be represented as the sum of the individual contributions of the anion and cation of the electrolyte
Kohlrausch Law of Independent Migration of Ions
Pause the video
Time duration: 3 minutes
Sol.
Kohlrausch Law of Independent Migration of Ions
12C03.4
PSV 1
Sol.
Summary
Reference Questions
NCERT In-text Questions: 3.7, 3.8, 3.9
NCERT Exercise Questions: 3.7, 3.8, 3.9, 3.10, 3.11
Workbook Questions: 1, 14, 16, 20
12C03.4 Conductivity of Electrolytic Solution
12C03.5
Batteries and Corrosion
Learning Objectives
Introduction of Batteries & Primary Batteries
Secondary Batteries & Fuel Cell
Corrosion
12C03.5 Batteries and Corrosion
12C03.5
CV 1
Introduction of Batteries
&
Primary Batteries
Introduction to the world of batteries
Chemical energy of the redox reaction is converted into electrical energy.
Batteries ???
Batteries
Primary Batteries
Secondary Batteries
Primary Batteries
The reaction occurs only once and after use over a period of time battery becomes dead and cannot be reused again.
Examples of Primary cells / batteries : Dry Cell , Mercury Cell
Dry cell
Mercury Cell
Dry Cell
At Anode :
At Cathode :
Carbon rod
(Cathode)
Zinc Cup
(Anode)
At Anode :
At Cathode :
Mercury Cell
Cell Can
Gasket
Separator
Cathode
Anode
Anode Cap
12C03.5
CV 2
Secondary Batteries
&
Fuel Cell
Secondary Batteries
It can be recharged by passing current through it in the opposite direction so that it can be used again.
Examples of Secondary cells / batteries : lead storage battery ,
nickel–cadmium cell
Lead Storage Battery
Nickel–Cadmium Cell
Lead Storage Battery
Anode
Negative plates : lead grids filled with spongy lead
Cathode
38 % Sulphuric acid Solution
At Anode
At Cathode
Reactions in Lead Storage Battery
Fuel Cells
Galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen, methane, methanol, etc. directly into electrical energy are called fuel cells.
ConcepTest
Ready for Challenge
Q. Write the reactions occurring during charging of lead storage battery.
Pause the video
Time duration: 2 minutes
Q. Write the reactions occurring during charging of lead storage battery.
At Cathode
At Anode
Sol.
12C03.5
CV 3
Corrosion
Corrosion
In corrosion, a metal is oxidised by loss of electrons to oxygen and formation of oxides.
Corrosion slowly coats the surfaces of metallic objects with oxides or other salts of the metal
Corrosion of iron in atmosphere
Oxidation of Fe
Atomospheric oxidation
Preventive Measures For Corrosion
Preventive Measures For Corrosion
By covering the surface with paint or by some chemicals (e.g. bisphenol)
By covering the surface by other metals (Sn, Zn, etc.) that are inert or react to save the object
By providing a sacrificial electrode of another metal (like Mg, Zn, etc.) which corrodes itself but saves the object
Simplest method to avoid corrosion is to prevent the surface of the metallic object to come in contact with atmosphere
Summary
With the help of batteries, chemical energy of the redox reaction is converted into electrical energy.
Primary batteries – Cannot be reused.
Secondary Batteries – Can be reused after charging.
In corrosion, a metal is oxidised by loss of electrons to oxygen and formation of oxides.
12C03.5 Batteries and Corrosion
Reference questions
NCERT Intext questions : 3.13, 3.14
Workbook questions : 6, 8, 15
Nernst Equation
Nernst Equation