What is the definition of Redox reaction. What is the definition of Oxidation reaction. What is the definition of Reduction reaction. How to Calculate oxidation number or oxidation State. What is Algebra method in redox reaction. What is Chemical bonding method. How many types of Redox Reaction

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What is the definition of Redox reaction?

A chemical reaction in which oxidation and reduction takes place is called a redox reaction. This chemical reaction is useful as well as harmful.

Example of redox reaction areas

1. Rancidity if food

1. Rusting of iron

1. Electrochemical reaction

1. Photosynthesis

What is the definition of Oxidation reaction?

A chemical reaction in which the following take place is called an oxidation reaction.

I) Gain of oxygen

ii) Loss of hydrogen

iii) Loss of Electron

iv) Increase oxidation number or oxidation state

v) Decrease Electron density

*Those which undergoes oxidation is called Reducing agent.

What is the definition of Reduction reaction?

A chemical reaction in which the following take place is called reduction.

I) Loss of oxygen

ii) Gain of hydrogen

Iii) Gain of Electron

Iv) Decrease oxidation number or oxidation state

V) Increase Electron density

*Those which undergoes Reduction act as an oxidation reaction.

CuO+H2———-Cu+H2O

CuO————Cu:-Reduction

Oxidising agent-CuO

H2——-H2O:-Oxidation

Reducing agent:-H2

How to Calculate oxidation number or oxidation State?

Charge on an atom in a compound when group or atom attached to it is remove this magnitude of the charge is called oxidation number or oxidation state. It is calculated by two methods:-

1. Algebra method of oxidation number

2. Chemical bonding method

Algebra method:- In elementary state oxidation number is zero but in the case of a charge, it is equal to the charge.

Such as:-

Au, Pu, S8, N2, Na, mg—-oxidation number=0

Al+³-oxidation number=(+3)

mg+²-oxidation number=+2

O-² -Oxidation number=-2

What is the Algebra method in a redox reaction?

How to Find oxidation number/ oxidation state using algebra method

Rule of algebra method

i) oxidation number of oxygen in any compound general taken – 2 but in the case of peroxide value is -1 and with fluorine value is positive.

ii) In any compound oxidation state (oxidation number) of fluorine is taken – 1.

iii) oxidation number of hydrogen is +1 with non-metal and -1 with metal.

iv) In any compound sum of the oxidation state is equal to the charge.

Ex-

KmnO4

=) 1+x-(2×4)=0 (K=+1,mn=x, O=-2)

=)x=+7

Oxidation number or oxidation state of mn=+7

How to find maximum and minimum Oxidation number /oxidation state and the periodic table

s-Block- Group=1- Oxidation number=+1

– Group=2- Oxidation number=+2

p-Block- maximum=V.E.=valence electrons

– minimum=V.E.-8

d-Block-min= s-Block Electrons (last)

-maximum= s-Block+unpaired electron in d.

f-Block=general+3

Note:- maximum= Oxidising agent

Minimum= Reducing agent

Intermediate Oxidising as well as a reducing agent.

Ex- Nitrogen

E.c. = 2, 5

Valence Electron=5

Block = p-Block

Maximum= 5

Minimum= V.E.-8=5-8=-3

Numbers=5,4,3,2,1,0,-1,-2,-3

In HNO3, N has a maximum Oxidising number. So, N is an oxidising agent.

Verification

HNO3

1+x-2×3=0

=)x=+5

What is the Chemical bonding method?

How to find oxidation number/oxidation state using Chemical bonding method

The chemical bonding method gives individual oxidation state/oxidation numbers. Whereas the Algebra method gives an average oxidation state.

Ex-H2S4O6

Verifications:-

-2 -2

O O

-1 -1 | | -1

H – O – S – S – S – S – O – H

| |

-2 -2

O O

S=+5

S=0

S=+5

Average=5/2

By Algebra method

1×2+4x-2×6=0

=)x=5/2

How many types of Redox Reaction?

1. What is Addition Reaction?

A chemical reaction in which two or more two elements or compounds combine and form a single compound is called an additional reaction.

C+O2=CO2 ( Addition Reaction) two or more two elements or compounds combine and form a single compound.

In LHS, Oxidation number (O2)=0

In RHS, Oxidation number (O2)=-2

Decreasement of oxidation number=0 to -2 (that’s why it is Reduction)

In LHS, Oxidation number (C)=0

In RHS, Oxidation number (C)=4

Increasement of oxidation number=0 to 4(that’s why it is Oxidation)

From the above, we can say it is also a Redox reaction.

CaO+CO2=Ca.CO3 =Addition(But not redox ) why?

Because oxidation and reduction both do not take place.

2. What is Decomposition Reaction?

A chemical reaction in which h single compound is split into two and more than two different Compounds is called a decomposition Reaction.

Ex- AgCl =(in presence of photos) =Ag+Cl2 (decomposition) (and also Redox) why? Because oxidation and reduction take place.

3. what is Displacement Reaction?

A chemical reaction in which more reactive metal or non-metal displace less reactive metal or non-metal in their salt solution is called displacement Reaction.

Chemical reaction those which not change their oxidation number is called spectator Ion. When spectator Ion is removed from the chemical reaction it converts into an ionic reaction.

CuSO4 (aq) + Zn (s) → Cu (s) + ZnSO4 (aq) (metal displacement) ( redox)

-2

Spectator Ion=SO4

Ionic reaction= Zn + cu+² = Zn+² + Cu

KBr+I2=KI+Br2 ( non-metal displacement Reaction)(Redox)

Spectator Ion=k+¹

-1 -1

Ionic reaction=2Br + I2=2I + Br2

4. what is Disproportionate Reaction?

A chemical reaction in which an atom of a single compound undergoes an s oxidation reaction, as well as s reduction reaction, is called a Disproportionate Reaction.

Conditions:-

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To be continued……