Redox reaction (Oxidation & Reduction) with example

Redox reaction (Oxidation & Reduction) with example

Redox reaction (Oxidation & Reduction) with example

Oxidation

It is defined as “Gain of oxygen, loss of hydrogen, loss of electrons and increase in oxidation state”.

Reduction

It is defined as “Gain of hydrogen, gain of electrons, loss of oxygen and decrease in oxidation state”.Where there is reduction there is always oxidation.

Examples of redox reaction

             1.                                 

 

 

Here iron oxide is reduced to Fe and reduction is done and carbon mono oxide is oxidize to carbon dioxide and oxidation is done.

                                                                                                                

2. Ethanol or ethyl alcohol is oxidize to ethanol by loss of hydrogen.

 

 

                               

 

 

3. Ethanol is reduced to ethanol or ethyl alcohol by gain of hydrogen.

 

                               

4. Here copper ion is reduced by gain of electron to copper and reduction has done. On the other hand Mg is oxidize to Mg⁺²ion by loss of electrons.

Rules for assigning oxidation state or oxidation number.

 Oxidation number is always written on the top of symbol.

• The oxidation state or oxidation number of all elements in a free state is zero. Such as O^o_2, Cl^o₂, S^o₈ etc.
• The sum of the oxidation state of all atoms or ions in a neutral compound is zero. Such as Nacl^o etc.
• The sum of the oxidation state of all the atoms in a molecular ion is always is equal to the charge on the ion.
• The more electronegativity atoms have negative oxidation state and less electronegativity atoms have positive oxidation state.

The oxidation state of some elements in a common groups are as follow

Groups	Elements	Oxidation state
1	Li, Na, K, Rb, Cs	+1
2	Be, Mg, Ca, Sr, Ba, Ra	+2
17	F, Cl, Br, I. At	– 1
16	O, S, etc.	Generally – 2
1	H	+1 but –1 in metallic hydrides