This document provides information about oxidation, reduction, and redox reactions. It defines oxidation as losing electrons and reduction as gaining electrons. It discusses oxidizing agents and reducing agents. Examples of oxidation and reduction in daily life are provided, such as corrosion and food rancidity. The document also explains how to determine oxidation states and balance redox reactions. An exercise with sample problems is given to help identify oxidation states.

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3. PHYSICAL CHEMISTRY
ORGANIC CHEMISTRY
INORGANIC CHEMISTRY

4. PHYSICAL CHEMISTRY ORGANIC CHEMISTRY INORGANIC CHEMISTRY
Atomic structure
Amount of substance
Bonding & state of matter
Energetics
Kinetics
Equilibria
Redox
Introduction to organic chemistry
Alkanes
Haloalkanes
Alkene
Alcohol
Organic analysis
Periodicity
The alkaline earth metal
The halogens

5. Admissions opened for GCSE (AQA and Edexcel Boards)
PHYSICAL CHEMISTRY ORGANIC CHEMISTRY INORGANIC CHEMISTRY
Thermodynamics
Kinetics
Equilibrium constant
Electrochemistry
Acids bases and buffers
Nomenclature and isomerism
Carbonyl compounds
Aromatic chemistry
Amines
Polymerization
Amino acids proteins and DNA
Organic synthesis and analysis
Structure determination and chromatography
Periodicity part-II
The transition metal
Reaction of inorganic
compounds in
aqueous solution

6. Oxidation. Reduction and Redox Reaction

7. Learning Objectives :-
 What is oxidation and reduction
 What is oxidation number.
 How to find out oxidation number.
 Understand about redox reaction.
 Type of redox reactions.
 How to balance the redox reactions.
In this lecture you will learn about...

8. 1.Electron:- It is lightest stable subatomic particle present in an atom , it
carries a negative charge of 1.6 x 10-19C.
2.Oxidising Agent:- The elements which reduced it self is called
oxidising agent.
3.Reducing agent:- The elements which oxidised it self is called
Reducing agent.

9. What is Oxidation?
• According to electronic concept oxidation is defined as the process in
which an atom or ion loses one or more electrons.

10. Classical Idea of Oxidation Reaction
Oxidation reactions involve:
1. Addition of oxygen:
C + O2 → CO2 (oxidation of carbon)
2. Addition of electronegative element:
Fe + S → FeS (oxidation of Iron)
3. Removal of hydrogen:
H2S + Br2 → 2 HBr + S (oxidation of sulphide)
4. Removal of electropositive elements:
2 KI + H2O2 → I2 + 2 KOH (oxidation of iodide)

11. What is Reduction?
• According to Classical or earlier concept reduction is a
process which involves the addition of hydrogen or any
electropositive element or the removal of oxygen or any
electronegative element.
• According to electronic concept reduction is defined as the
process in which an atom or ion gains one or more electrons.
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12. Classical Idea of Reduction reactions
1. Addition of hydrogen:
2. Addition of electropositive element:
SnCl2 + 2HgCl2 → SnCl4 + Hg2Cl2 ( reduction of mercuric chloride)
3. Removal of oxygen
ZnO + C → Zn + CO (reduction of zinc oxide)
4. Removal of electronegative element
2FeCl3 + H2 → 2FeCl2 + 2HCl (reduction of ferric chloride)
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13. Oxidation and Reduction in terms of Electron Transfer
…………………

14. Oxidising And Reducing Agent
, or oxidant, gains electrons and is reduced in a chemical
reaction. Also known as the electron acceptor. Examples- halogens, potassium
nitrate, and nitric acid.
, or reductant, loses electrons and is oxidized in a chemical
reaction. A reducing agent is oxidized, because it loses electrons in the redox
reaction. Examples- The earth metals, formic acid, and sulfite compounds.

15. Rancidity of foods
Rancidity means the spoilage
caused to the food items making it
undesirable for consumption
In Photosynthesis
Corrosion of metals
Corrosion is rusting of iron
the smell and taste of
food items changes
when oxidised.
The black coating on silver
and green coating on
copper
OXIDATION AND REDUCTION
EFFECT IN DAILY LIFE
Examples of Corrosion
Example of Rancidity
4Fe + 3O2 + 6H2O → 4Fe(OH)3

16.  Word Redox is short for Reduction and Oxidation.
REDOX REACTION
 Redox reaction is related to gain or lose of electrons
Zn is oxidised to Zn2+ so Zn is reducing agent Cu+ is
reduced to copper so Cu2+ is an Oxidising agent
 Zn2+ +Cu Zn + Cu2+

17. TYPE OF REDOX REACTION
Combination Reaction
Decomposition Reaction
Displacement Reaction
Disproportionate Reaction

18. Choose the type of reaction
4KclO3 3KclO4 + Kcl
Na2SO3 + Na3AsO3 +O2 Na2SO4 Na2SO4 Na3AsO4
Cu +2HNO3 Cu(NO3)2 +2NO2 + H2O
S +O2 SO2

19. How to calculate oxidation number
Oxidation states are used to see what has been oxidized and what has been
reduced in redox reaction.
following points are important to determine the oxidation number
The oxidation number of an atom in pure elemental form is
considered to be zero. e.g., H2, O2, Na, Mg
Oxidation number of any element in simple monoatomic ion will
be equal to the charge on that ion, for example, oxidation number
of Na in Na+ is +1.
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20. • Oxidation number of oxygen is generally –2 but in case of peroxide (H2O2)
oxygen has oxidation number –1. In a compound OF2 the oxidation number of
oxygen is +2.
• The oxidation number of alkali metals (Na, K) and alkaline earth metals (Ca, Mg)
are +1 and +2 respectively.
• The oxidation number of halogens is generally –1 when
• they are bonded to less electronegative elements.
How to calculate oxidation number
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21. • Oxidation number of hydrogen is generally +1 in most of its compounds but in
case of metal hydride (NaH, CaH2) the oxidation number is hydrogen is –1.
• The algebraic sum of the oxidation numbers of all the atoms in a neutral
compound is zero. In an ion, the algebraic sum of oxidation number is equal to
the charge on that ion.
How to calculate oxidation number
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22. EXERCISE TO CALULATE OXIDATION NUMBER
Q1: What is oxidation number of Xe in XeO3 and XeF6 respectively
a)+4 b)+6
c)+1 d)+3
Q2: In which of the following compound cl show +5 oxidation number
a)HclO4 b)HclO3
c)HclO d)HclO2
Q3: What is oxidation number of S in Na2S4O6 .
a)+2/3 b)+3/2
c)+3/5 d)+5/3

23. EXERCISE TO CALULATE OXIDATION NUMBER
Q4: What is oxidation number of As in H3AsO4.
a)+5 b)+6
c)+1 d)-3
Q5: When potsium permangnate react with oxalic acid then oxidation
number of Mn change from
a)+7 to +2 b)+7 to +4
c)+7 to +5 d)+6 to +2
Q6: What is oxidation number arrangement is .
a)OF2<KO2<BaO2<O3 b)BaO2<KO2<O3<OF2
c)KO2<OF2<O3<BaO2 d)OF2<O3<KO2<BaO2

24. Balancing the redox reaction
Cu +HNO3 Cu(NO3)2 +2NO2
H2O2(aq)+Cr2O7
2−(aq) → O2(g)+Cr(aq)3+

25. Balancing the redox reaction
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26. Balance the given redox reaction
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27. Evaluation
Q1. What is known as Autooxidation?
(a) Formation of H2O by the oxidation of H2O2.
(b) Formation of H2O2 by the oxidation of H2O.
(c) Both (1) and (2) are true (d) None of the abov
Q2.The tendency of an electrode to lose electrons is known as
(a) Electrode Potential (b) Reduction Potential
(c) Oxidation Potential (d) E.M.F.

28. Q3.Which of the following processes does not involve either oxidation or
reduction?
(a) Formation of slaked lime from quick lime
(b) Heating Mercuric Oxide
(c) Formation of Manganese Chloride from Manganese oxide
(d) Formation of Zinc from Zinc blende
Q4.The oxidation state of Cr in Cr (CO)6 is
(a) 0 (b) 2
(c) 2 (d) 6

29. Q5.Which of the following processes does not involve oxidation of iron?
(a) Formation of Fe(CO)5 from Fe.
(b) Liberation of H2 from steam by iron at high temperature.
(c) Rusting of iron sheets.
(d) Decolourisation of blue CuSO4 solution by iron.
Q6.Which of the following reactions does not involve either oxidation or reduction?
(a) VO2
+ → V2O3
(b) Na → Na+
(c) CrO4
2- → Cr2O7
2-
(d) Zn2+ →Zn

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