# REDOX REACTIONS

Chemical reaction in which electron transfer from one chemical substance to another are termed as oxidation-reduction reactions or redox reactions. You can see many examples from your daily life like production of electricity in batteries , production of heat by burning chemical substances , electroplating , manufacturing of useful products caustic soda, potassium permanganate etc

NOTE : Oxidation reduction reactions are complementary to one another , no single oxidation reaction is known , no single reduction reaction is known.

### Oxidation Reaction

Oxidation reaction is a process which involves :

$2Mg+O_{2}^{*}=2MgO~[oxidation~of~magnesium]\\S+O_{2}^{*}=SO_{2}~[oxidation~of~sulphur]$

(b) Removal of hydrogen

$H_{2}S+Cl_{2}^{*}=2HCl+S~[oxidation~of~hydrgen~sulphate]\\4HI+O_{2}^{*}=2H_{2}O+2I_{2}~[oxidation~of~hydrogen~iodide]$

(c) Addition of a electronegative element

$Fe+S_{2}^{*}=FeS~[oxidation~of~iron]\\SnCl_{2}+Cl_{2}^{*}=SnCl_{4}~[oxidation~of~stannous~chloride]$

(d) Removal of an electronegative element

$2KI+H_{2}O_{2}^{*}=2KOH+I_{2}~[oxidation~of~potassium~iodide]\\2K_{2}MnO_{4}+Cl_{2}^{*}=2KCL+2KMnO_{4}~[oxidation~of~potassium~manganate]$

(*) sign in above equation show oxidising agents. Oxidising agents are the substance which brings oxidation.

### Reduction Reaction

Reduction reaction is a process which involves :

(a) Removal of oxygen