Chemical Change Types: Interesting Analysis

The chemical change is the transformation of a molecule into an entirely different molecule.

There are principally three fundamental chemical change types: inorganic, organic, and biochemical changes. The chemical reactions can also be further branched into – synthesis, decomposition, single displacement, and double displacement.

In this segment, we shall intend to learn about the different chemical change types.

Inorganic Changes

Inorganic type changes describe all reactions that do not involve carbon in them.

This type of reaction typically involves the process of neutralization that is an acid- base reaction, redox reactions that involve oxidation and reduction, Decomposition reactions and displacement reactions about which we will further try to understand in this article.

There are numerous applications of inorganic changes that mainly occur in laboratories and industries.

There are a vast number of applications and to name a few:

  • Ammonia – a rich source of fertilizer. It is also used in nylons, plastics, fibre, hydrazine (used as rocket and jet fuel), etc.
  • Titanium Dioxide – used as white powder based pigment in paints, coatings, plastics, paper, inks, fibre, foods, cosmetics, photocatalysts, etc.
  • Chlorine – used for pipes, clothes, furniture, fertilizer, insecticide, water treatment, sterilization, etc.

Organic Changes

The organic types of changes describe all reactions involving carbon in them.

This type of reactions typically involves the process of halogenations – reactions dealing with halogens, polymerization – monomers to polymers, condensation reaction – loss of water, methylation – adding a methyl group to a substrate, etc.

Applications of organic changes:

Like inorganic changes, organic changes also have a large number of applications. As we know that organic changes are the changes that involve carbon and its compounds; identifying its applications are easy.

  • Diamond – diamond is largely used in the fashion industry as jewellery, also used for cutting and drilling as it is extremely hard.
  • Amorphous Carbon – used to make paints, inks and batteries.
  • Graphite – used as lead in pencils.
  • Coal – used as fuel.

The examples mentioned above are all different allotropes of carbon.

Bio- chemical Changes

Changes that occur in living organisms such as humans, plants, animals, and other organisms are all categorized under bio- chemical change.

These types of reactions typically involve the process of photosynthesis – plants convert light energy into chemical energy, digestion of food, protein synthesis – the creation of protein in molecules, etc.

Usually, bio- chemical changes are naturally occurring and cannot be artificially synthesized. Though, with the rise of new technologies, there’s a lot of room for new inventions. But, that is still in process. For now, one can jolt up a reaction but not synthesize it.

Thus, the application of bio- chemical change and its examples are the same, such as the process of photosynthesis, the process of digestion of food, the process of protein synthesis, etc.

Read more on Chemical Change Examples

There are four basic classes of chemical reactions about which we will learn in this section of the article.

Chemical reactions are further fractionated as – synthesis, decomposition, single displacement, and double displacement.

Chemical Change Types
General Equation for types of Chemical Reactions

1. Synthesis

In a chemical synthesis, two or more reactants combine together for the creation of a complex product. In other words, it can also be expressed as two molecules interacting with each other to form a single complex molecule. The chemical properties of this newly formed product will be different from both the reactants.

This reaction is also referred by the name – combination reaction. The common equation for the reaction is given as:


One of the most common examples of this reaction is the formation of salt, which we use in our day- to- day lives.


Another easy yet most important example is the formation of water.


Applications of a synthesis reaction:

It is easy to identify the applications of such easy examples. Yet another example that we observe more often is the rusting of iron, in which iron combines with oxygen to form rust. Synthesis reaction has a wide range of applications, as innumerable products can be obtained by combining various chemical elements from the periodic table.

2. Decomposition

A reactant is broken down into two or more simpler products in the decomposition reaction. These reactions need energy in the guise of heat, light, or electricity to disrupt the bonds within the reactants.

The general equation for this reaction is given as:


It can be stated that the decomposition reaction is the rearward reaction of the combination reaction. And thus, we can take the same example of water, but instead, this time, we separate hydrogen and oxygen from the water through the electrolysis process.


The electrolysis process is nothing but enhancing the reaction with the help of electricity.

Another quintessential example of decomposition reaction can be splitting calcium carbonate into carbon dioxide and calcium oxide.

CaCO3→Calcium Oxide(CaO)+Carbon Dioxide(CO2)

Decomposition reaction would not necessarily yield two or more single products. Occasionally, the products formed might still be a compound, just like the reaction mentioned above. Such reactions are still considered to be decomposition reactions.

Decomposition reaction can be both endothermic (heat- absorbing) as well as exothermic (heat- releasing).

For instance, the decomposition of nitrogen oxide into nitrogen and oxygen is exothermic or heat- releasing, while the decomposition of ozone (O3) into dioxide (O2) and oxygen (O) is endothermic or heat- absorbing.

Applications of decomposition reaction include:

  • Metal extraction from ores
  • Manufacture of cement
  • Manufacture of calcium oxide
  • Thermite welding
  • Acid indigestion relief

Read more on How Can a Chemical Change be Reversed

3. Single replacement

In a single displacement reaction, one reactant gets replaced by another reactant, which is why this reaction is well known as a substitution reaction.

The general equation for this reaction is given as:


From the above equation, we can see that reactant ‘C’ has replaced reactant ‘B’ and formed new products. In such a reaction, the same types of reactants are usually replaced. For example, metal replaces metal; non- metal replaces non- metal, etc.

Here, the more reactive element replaces the less reactive.

Let’s us try to understand this reaction with the help of an example.

The mixture of zinc with hydrochloric acid yields zinc chloride and hydrogen.


As zinc is a stronger element than hydrogen, it will replace hydrogen and bond with chlorine.

Substitution reactions are further identified into two types:

  1. Nucleophilic substitution reaction
  2. Electrophilic substitution reaction

Let us try to understand these reactions in brief.

  1. Nucleophilic substitution reaction

Nucleophile means nucleus loving or electron- rich element. The replacement is the same as the simple replacement. Here, a stronger Nucleophile replaces a weaker Nucleophile.

  1. Electrophilic substitution reaction

Electrophiles are electron loving. They look for available electron pairs for bonding. They seek nucleophiles as they want to give away their electrons.

Applications of single replacement reactions:

  • Used for making steel.
  • Also used in thermite welding
  • Metal extraction
  • Nucleophiles and Electrophiles are used in various industrial, pharmaceutical and agrochemical processes.

4. Double replacement

In double replacement, two reactants replace each other to form new products. It is also known as metathesis. In this reaction, cations (Positively charged ions) and anions (Negatively charged ions) replace each other, but not both together.

It generally occurs with reactants that are aqueous or dissolved in a liquid solution, which is usually water. One of the products without exception is in the form of a gas, or a precipitate, or molecule such as water.

The general equation for this reaction is given as:


Here we can assume that reactants ‘A’ and ‘D’ are cations, and reactants ‘B’ and ‘C’ are anions.

Let’s take the example of a double replacement reaction to understand it better.

The mixture of sodium hydroxide with hydrochloric acid yields sodium chloride and water.

Thus, the cation of one substance makes pair with the anion of another substance.

Applications of double replacement reactions and single replacements reactions are almost similar. Such as:

  • Thermite welding
  • Metal extraction
  • Replacement of metals from aqueous salt solutions.
  • Photosynthesis
  • Combustion
  • Iron rusting
  • Acid- base reaction

Durva Dave

I am Durva Dave, completed my post-graduation in Physics. Physics fascinates me a lot and I like in knowing the ‘Why’ and ‘How’ of everything that unfolds in our universe. I try to write my blogs in simple yet effective language so that it is easier for the reader to understand as well remember. I hope with my curiosity I am able to provide the readers for what their looking for through my blogs. Let’s connect through LinkedIn.

Recent Posts