What is Redox Reaction Class 10

After learning oxidation and reduction reactions, we must know what is  redox reaction. So today we will learn the definition and examples of redox reactions in detail.

Redox reaction definition

Oxidation reactions and reduction reactions take place simultaneously means at the same time, so the reaction is called a reduction-oxidation reaction or redox reaction.

                                          Or

Those reactions in which oxidation and reduction take place at the same time are called redox reactions.

   2H₂  + O₂  →2H₂O

In the above reaction, oxygen is added to hydrogen so it is oxidised to `H_2O`.

At the same time, hydrogen is added to oxygen so it is reduced to `H_2O`.

Redox Reaction in terms of electron transfer

On the basis of the electron transfer method, we can understand redox reaction easily

Let’s take the example of rusting iron

4Fe + xH₂O + 3O₂ → 2Fe2O3.xH₂O

In the presence of moisture (`H_2O`), iron loses electrons and becomes a positively charged ion.

Oxidation reaction-  iron is oxidized after losing electrons.

          Fe   →  Fe²⁺  + e^-

Now these electrons are accepted by oxygen present in water.

Reductio reaction - oxygen is reduced after accepting electrons

   O₂ + 4e^-   +4H⁺ → 2H₂O

These Fe²⁺ ions react with OH^- ions in water to produce iron hydroxide which will produce rust in several days. This is rusting of iron.

 Fe²⁺  + OH^- →Fe(OH)₂ →  Fe₂O₃

                                              (rust)

 

 

Redox Reaction examples

1.  Reaction between ZnO and carbon

ZnO + C →Zn  + CO

Zinc oxide is reduced to zinc metal and carbon is oxidised to carbon monoxide.

2.  Reaction between copper and silver nitrate

Cu + 2AgNO₃   →2Ag  + Cu(NO₃)₂

Copper metal is oxidised to copper nitrate and silver nitrate is reduced to silver metal.

3.  Reaction between manganese dioxide and aluminium

3MnO₂  + 4Al →3Mn  + 2Al₂O₃

Manganese dioxide is reduced to manganese and aluminium metal is oxidised to aluminium oxide.

4.  Reaction between hydrogen sulphide and sulphur dioxide

2H₂S   + SO₂  →3S   + 2H₂O

Hydrogen sulphide is oxidised to water and sulphur dioxide is reduced to sulphur.

5.  Reaction between manganese dioxide and hydrochloric acid

MnO₂  +  4HCl →MnCl₂  +   2H₂O   + Cl₂

Manganese dioxide is reduced to manganese chloride and hydrochloric acid is oxidised to chlorine.

6.  Reaction between ferric oxide and aluminium

  

Fe₂O₃    + 2Al  →2Fe    + Al₂O₃

 Ferric oxide is reduced to iron metal and aluminium is oxidised to aluminium oxide.

7.  Reaction between copper and iodine

    

Cu  + I₂  →   CuI₂

   Copper is oxidised to copper iodide and iodine is reduced to copper iodide.

8.  Reaction between hydrogen and chlorine

H₂   +Cl₂    →  2HCl

Hydrogen is oxidised to hydrochloric acid and chlorine is reduced to hydrochloric acid.

9.  Reaction between iron and sulphur

Fe  + S   →FeS

Iron is oxidised to ferrous sulphide and sulphur is reduced to ferrous sulphide.

10.      Reaction between magnesium and oxygen

2Mg   + O₂  →2MgO

 Magnesium is oxidised to magnesium oxide and oxygen is reduced to magnesium oxide.