As we know Chemistry is an incredible subject that came into existence millions of years ago. Chemistry involves the study of different compounds, their reactions under various conditions, the atomic structure of the compound along with their molecular formulas. There are some reactions that have revolutionized the chemistry field. Basic theories like molecular orbital theory, covalent bond theory and many more theories have laid the proper shape to the study of the subjects. A reaction like Redox reactions which involves processes like reduction and oxidation is explained in detail in this article. It is a reaction where the oxidation number of the reactant or the reacting chemical changes. Transfer of electrons takes place between the chemical reactant which undergoes oxidation reaction and the other chemical species undergoes oxidation.
When concepts like atomic structure, atomic number, and ions are studied, there comes a concept Lanthanoid contraction which deals with the decrease in the size of atoms and ions of the rare earth elements ranging from atomic number 57 Lanthanum to atomic number 71 Lutetium. The ionic radii or atomic size of tri positive lanthanide ions decrease steadily from La to Lu because of the increasing nuclear charge and electrons entering inner (n-2) f orbital. This process of the gradual decrease in the atomic size with increasing atomic number is called lanthanide contraction.
Let us know in detail about redox reaction.
In a redox reaction electrons transfer is witnessed between 2 reactants that are involved in the chemical reaction. This transfer of electrons could be identified by watching the changes in the oxidation states of the reactants involved in the chemical reaction. Reduction-oxidation reaction is known as Redox reaction. In a chemical reaction, where the reactants get reduced is known as the oxidizing agent and the reactant that gets oxidized is known as the reducing agent.
Redox reaction is represented as shown in the figure below.
Combustion is an ideal example of a redox reaction. This process takes place instantaneously with the generation of a considerable amount of light and heat. Combustion exactly means burning. Burning of a material is an example of a redox reaction.
Example: This chemical reactions shown below describes the process of burning of coal and gasoline
C + O 2 → CO 2
2 C 8 H 18 + 25 O 2 → 16 CO 2 + 18 H 2 O
A process like decay takes place when an animal or plant dies. The organic compounds seen in animal or plant begins to react with oxygen in the environment slowly and the reaction seen is known as decay process. Decay is also one of the examples of redox reaction which consumes comparatively more time to complete. Animals and plants are composed of organic compounds like oxygen, hydrogen, and carbon. x, y, and z alphabets used in the reaction represent the number of atoms in the reaction like carbon, hydrogen, and oxygen. The equation shown below describes the process in which decay takes place:
C x H y O z + O 2 → CO 2 + H 2 O
Rust is developed on the material when iron reacts with oxygen resulting in the formation of oxides. Rust is the name given to the oxide of iron and for the oxides of other metals too. Corrosion is a way in which rusting process takes place and is comparable to processes like combustion.
The equation given below clearly represents the process of rusting of iron.
4 Fe + 3 O 2 → 2 Fe 2 O 3
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