Decomposition Reaction Types Definition and Examples

In this article, we are going to learn what is decompositon reaction and what are the types pf decompostion reaction.

Reaction includes reactant, favorable condition and results in products. There are different types of chemical reactions that we had studied earlier and among those Decomposition reaction was one of them. There are several other types of decompostion reaction also. Today in this post, we are going to learn decomposition reaction definition and what are the types of decomposition reaction. We will also see different application of chemical reaction. No without wasting more time, lets get jump into the definition.

Decomposition Reaction With Examples

What is Decomposition Reaction

In a reaction in which, one compound breaks down into two or more simpler compounds. This reaction can also be known as the opposite of a composition reaction. In other words, it can also be considered as a reaction in which reactants on providing activation energy breaks down /decomposed to products.

Example of Decomposition Reaction

H2CO3 (aq.) → CO2 (g) + H2O (l)

This is an example of decomposition reaction in which carbonic acid (H2CO3) is breakdown into carbon dioxide and water. Here carbonic acid (H2CO3) is a reactant and on decomposition, it results in product Carbon dioxide and water.
Read additional examples at Wikipedia

Double Decomposition Reaction

A reaction in which two-component decompose and interchange position and form a new compound known as a double decomposition reaction. Component change position where positive ion change position with positive and negative with negative ion.

AB + CD → AC + BD

Types of decomposition reaction

There are total of 3 types of decomposition reactions are there and these types are based on the mode of energy required to the completion of process. Types of are enlisted along with explanation and examples.

  1. Thermal decomposition reaction | Thermolysis
  2. Electrolytic decomposition reaction | Electrolysis
  3. Photo decomposition reaction | Photolysis
Decomposition Reaction Types

Now let us understand all the types of one by one in details with examples

1. Thermal decomposition reaction

Thermal means heat and decomposition mean breakdown of substances. A thermal decomposition reaction is a type of reaction in which a reactant is decomposed when heated. When heat is supplied to the reactant, chemical bonds break and this results in the breakdown of the reactant into the product. The thermal decomposition reaction is also known as thermolysis. These reactions are the endothermic type of reaction as it requires external heat for reaction.

Thermal Decomposition reaction examples

CaCO3 → CaO + CO2

In the above reaction, calcium carbonate when heated for thermal decomposition, calcium oxide along with carbon dioxide will produce.

2. Electrolytic decomposition reaction

In a chemical reaction in which, electricity is passed through the aqueous solution of the reactant, an electrolytic reaction occurs and results in the breakdown of the reactant into the product is known as an electrolytic reaction. This reaction is also known as the electrolysis reaction.

Electrolytic Decomposition Reaction

Electrolysis of H2O (Water)

 H2O → H2 + O2

In above reaction, when electric charge is passed in the water, electrolysis of water occurs and oxygen and Hydrogen is produced.

Electrolysis of NaCl (Sodium Chloride)

NaCl → Na + Cl

A decomposition reaction of sodium chloride will occur when electricity is passed to the aqueous solution of sodium chloride (NaCl), and sodium and chlorine will form. We had discussed the chloralkali process in which electrolysis reaction in used.

3. Photo decomposition reaction | Photolysis

In this type of reaction, light or photons are used to break down the reactants into several products. The decomposition reaction that takes place due to the action of light is known as photodecomposition reaction. These reactions are also known as photolysis. In these reactions, absorption of light excites electrons and results in the breaking of bonds and creating products.

Photolysis reaction example

2AgCl → 2Ag + Cl2

The above reaction is an example of a photolysis reaction example in which, Silver chloride decomposes in presence of light and form silver metal along with chlorine.

Applications of Decomposition Reactions?

These reactions are widely used in the manufacturing of various products. Electrolysis is a process in which an electrolytic type of decomposition is used. In Chloro -Alkali industries, electrolysis of brine i.e. NaCl is performed for the preparation of Sodium Hydroxide (NaOH) and along with caustic, Hydrogen, and chlorine is also produced. Here are some of the uses

  1. In chloro-Alkali industries
  2. To extract metals from ores

FAQ (Frequently asked question)

1. Why are decomposition reactions endothermic?

Not all decomposition reactions are endothermic, Thermal Decomposition reaction which requires heat to break down bonds are usually endothermic reaction.

2. What occurs during decomposition reaction?

As definition states, in this reaction, bonds of reactant breaks and it results in breakdown of reactant into products.

Wrapping Up

These were the detailed article on what is decomposition reaction definition and types of decomposition. There are several applications of reaction and are widely use in chemical industries for the manufacturing of products. If you are interested in chemical engineering or chemistry then do check our other article like types of chemical reactions where we discussed several reaction types with examples. You can also check types of reactors used in industries and their application. Download our official android app to stay updated with chemical engineering articles and Industrial safety topics also.

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Me - Founder of Chemical Tweak - A Chemical Engineer by profession and a part-time self-trained technology blogger.

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