Synthesis Reaction: Definition, Examples, Characteristics

To understand synthesis reactions, let’s dive into the intriguing world of combining elements and compounds to form new products. In this section, we will explore the definition of a synthesis reaction, delve into an example that brings it to life, examine the general form it takes, highlight the characteristics unique to synthesis reactions, explore common examples, discuss how to recognize them, and finally, discover their significance in the realm of organic chemistry. Let’s embark on this chemical journey together!

What is Synthesis Reaction?

Synthesis reaction is one type of chemical reaction in which two different atoms involve in the reaction, react with each other to form a totally different molecular compound. In most of the synthesis reaction, energy is released from the reaction medium and known as exothermic reaction.

synthesis reaction example
Synthesis Reaction

Types of Synthesis Reactions

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To understand the different types of synthesis reactions, let’s delve into the world of chemical reactions. In this exploration, we will encounter the following sub-sections: combination reaction, single replacement reaction, and decomposition reaction. Get ready to uncover the fascinating world of chemical synthesis!

Combination reaction

Two or more elements can form a brand-new compound. This is called a synthesis reaction. It happens when different elements merge and create a compound with its own properties. Check out this example in a table:

Element 1Element 2New Compound
CarbonOxygenCarbon Dioxide

In the table, you can see how elements combine to make new compounds. For example, oxygen plus hydrogen gives water. Also, carbon plus oxygen creates carbon dioxide. Finally, sodium plus chlorine makes salt.

These synthesis reactions have been important for many years. For instance, people found out the water was a compound of hydrogen and oxygen, and this changed chemistry. This allowed us to figure out what substances were made of, leading to more scientific advances in different areas.

Finding the ideal partner for a new relationship is like a single replacement reaction – chemistry at its wildest!

Single replacement reaction

Say goodbye to the old, ’cause a single element is about to arrive! It’ll replace one of the elements in the compound and create a new one! This type of reaction is called a Single Replacement Reaction or a substitution reaction.

Let’s review what’s essential to know about it:

  • Reactants: Made up of a compound and an element that will replace one of the elements in the compound.
  • Products: A new compound and an element that has replaced one of the original elements.
  • Activation Energy: The minimum amount of energy needed for the reaction to occur.
  • Catalysts: Substances that increase the rate of reaction without being consumed in the process.
  • Redox Characteristics: Single Replacement Reactions involve oxidation and reduction reactions simultaneously.

In synthesis reactions, a single element daringly replaces another within a compound, resulting in a new compound. We witness the elements’ versatility and their quest for stability. This mesmerizing exchange offers us insights into chemical reactions. Scientists delve deeper to uncover details about elements’ behavior and their bond-forming willingness.

Interesting fact – Single Replacement Reactions play a critical role in biological processes. For example, redox reactions (a type of single replacement reaction) are involved in cellular respiration, where glucose and oxygen react to produce carbon dioxide, water, and energy (ATP).

Curiosity tugs at our sleeves, beckoning us to explore further. Embrace this opportunity and delve into the captivating world of synthesis reactions. Let your scientific imagination run wild as you uncover hidden treasures in compounds formed from daring element replacements.

Decomposition reaction

Let’s dive deep into the world of decomposition reactions with a table of information:

ReactantsCompounds that break down.
ProductsComponents after the decomposition.
CatalystsSubstances that speed up the reaction without being consumed.
TemperatureHeat required to start the decomposition.
PressureForce used during the process.

When a compound breaks down into simpler substances, it undergoes a synthesis reaction. This process involves the breaking of chemical bonds. New compounds or elements are formed. Decomposition can happen due to thermolysis, photolysis, and electrolysis. Each has unique characteristics and requirements, which determine the products of the reaction.


  1. Calcium carbonate: Calcium oxide + Carbon dioxide
  2. Hydrogen peroxide: Water + Oxygen
  3. Sodium chloride: Sodium + Chlorine

To make these synthesis reactions more efficient and controllable, here are some suggestions:

  1. Control temperature
  2. Use catalysts
  3. Optimize light exposure
  4. Manage electrolysis conditions

These ideas have been used in industrial processes, laboratory-scale reactions, and everyday applications. The ability to break down compounds into simpler substances has advanced chemistry and other related scientific disciplines.

Example of Williamson Synthesis

Synthesis of ethyl methyl ether

Williamson synthesis process is the best method to synthesis ethyl methyl ether (CH3-O- CH2CH3). This reaction proceeds through SN2 pathway. To obtain ethyl methyl ether as the synthesized product, sodium methoxide (CH3ONa) and ethyl chloride (C2H5Cl) reacts with each other. Sodium methoxide acts as nucleophile and attacks the electrophilic centre of ethyl chloride to eliminate the leaving group (Cl). Ethyl methyl ether is obtained as the Williamson synthesized product.

image 93
Synthesis of Ethyl Methyl Ether


Synthesis of anisole

This ether can also be synthesized by Williamson ether synthesis. To obtain anisole, sodium phenoxide (C5H5ONa) will react with methyl iodide (CH3I) and sodium phenoxide (nucleophile) attacks the electrophilic centre of methyl iodide. Iodide (I) will be eliminated as it is a good leaving group and anisole is formed.

Synthesis of Anisole

To know more please check: 12+ Exothermic Reaction Examples: Detailed Explanations

Synthesis of 2-Ethoxynaphthalene

To proceed this reaction, hydroxyl group should be inserted at the 2 position of naphthalene group and reacts with bromoethane. The reaction medium should be basis. Thus, sodium hydride (NaH) is used. Nucleophilic oxygen atom of OH group in naphthalene attacks the CH2 centre of CH3CH2Br and Br is eliminated as the leaving group.

image 92
Synthesis of 2-ethoxynaphthalene

Synthesis of Phenyl Propyl Ether

To synthesis phenyl propyl ether the reactants that are chosen are phenol, sodium metal and n-propyl bromide. Solvent that is used in this synthesis reaction is a polar aprotic solvent. The first step is to react phenol with sodium to form sodium phenoxide (active nucleophile). This nucleophile reacts with n-propyl bromide (electrophile) to synthesize phenyl propyl ether after elimination of bromide ion.

image 91
Synthesis of Phenylpropyl ether

 To know more please follow: 11+ First Order Reaction Example: Detailed Explanations

Synthesis of Benzyl-tertbutyl ether

William synthesis pathway is followed for the formation of benzyl-tertbutyl ether. Sodium tert-butoxide and benzyl bromide is taken as the reactants. O ion from sodium tert-butoxide attacks the electron deficient centre of benzyl bromide Br is eliminated as the leaving group to form the desired product.

image 90
Synthesis of benzyl tert-butyl ether

Synthesis of tert-butyl methyl ether

This synthesis process almost similar to the synthesis of benzyl tert-butyl ether. One of the reactants is also same, sodium tert-butoxide and the another reactant is methyl bromide (CH3Br). Tertiary sodium tert butoxide reacts as nucleophile and attacks the methyl carbon center to eliminate bromide ion.

image 89
Synthesis of t-butyl methyl ether

To know more please go through: 10+ Covalent bond types of elements: Detailed Insights And Facts

Synthesis of Ethoxy Benzene

In this process of synthesis of ethoxy benzene, Williamson synthesis process is followed. Sodium ethoxide reacts with phenyl bromide to form ethoxy benzene. O attacks the electrophilic centre of phenyl bromide and ethoxy benzene is obtained.

image 88
Synthesis of Ethoxy benzene

Synthesis of Cyclopentyl methyl ether

In this Williamson ether synthesis, cyclopentanol and methyl bromide is reacted with each other in a basic medium. In presence of base, hydrogen in O-H bond is eliminated and O attacks the methyl bromide to form the cyclopentyl methyl ether.

image 87
Synthesis of cyclepentyl methyl ether

Example of Balanced Synthesis

Synthesis of Water

Hydrogen and oxygen-these two gases are the two main reactants of this synthesis. Water molecule that is formed is also in gaseous state. Two molecules of hydrogen react with one molecule of oxygen to form water molecule. Dissociation of water is taken place by passing electric through water.

 2H2 +O2 = 2H2O

Electrolysis of water results-

  • Reduction at cathode: 2H+ (aq) +2e = H2 (g)
  • Oxidation at anode: 2H2O = O2 (g) + 4H+ (aq) + 4e
  • Net balanced equation: 2H2O= 2H2 + O2

Synthesis of Carbon-dioxide

Carbon dioxide is synthesized during the different decay process of various different material and fermentation of sugars. It can be produced by combustion process of wood or other organic materials. Another procedure is to react metal carbonates with dilute acid for the formation of water. For example, carbon dioxide can be synthesized by the reaction between sodium carbonate with dilute HCl.

Synthesis of Ammonia

Haber-Bosch process is the most well known process to synthesize ammonia. High pressure and high temperature is the two most important driving force of ammonia production. It is an exothermic process (del H= -91.8 KJ/mol). Ammonia is widely used as fertilizer.

N2(g) + 3H2 (g) = 2NH3

To know more please check: Disulfide reduction: How, What, Methods and Several Facts

Synthesis of Aluminium oxide

Aluminium hydroxide is the main reactant for the formation of aluminium oxide. Solid Al(OH)3 is decomposed over 11000C and form aluminium oxide (Al2O3). Besides that aluminium is oxidized in presence of oxygen to form aluminium oxide.

2Al(OH)3 = (Al2O3) + 3H2O

4Al (s) + 3O2 (g)= 2Al2O3

Synthesis of Iron Sulfide

Iron after reaction with sulfur forms iron sulfide (pyrrhotite) in presence of heat energy. Iron sulphide (FeS) has totally different physical and chemical properties with respect to two reactants, iron and sulphur. The ratio of iron with sulphur is 1:1. Equal amount of iron is reacted with equal amount of sulphur to form iron sulphide.

Fe + S = FeS

Synthesis of Potassium Chloride

Potassium chloride is basically an ionic salt. It can be synthesized by the reaction bases of potassium like potassium hydroxide (KOH) with strong acid, hydrochloric acid. In this synthesis reaction, strong acid (HCl) is completely neutralized by strong base (KOH). Water is also produced along with the KCl.

KOH (aq) + HCl (aq) = KCl (s) + H2O (liq)

Formation of Rust

Rust is reddish brown iron oxide formed by reacting iron with oxygen. Water or air takes part in this synthesis reaction as catalyst. Chemical formula of rust is Fe2O3.Nh2O and iron oxide hydroxide (FeO (OH),Fe(OH)3).

  • Fe(OH)2 = FeO + H2O
  • Fe(OH)3 = FeO(OH) + H2O
  • 2FeO(OH) = Fe2O3 +H2O

Synthesis of Calcium Carbonate

In this synthesis reaction, calcium oxide (CaO) and carbon dioxide is reacted to form calcium carbonate. At first step, calcium hydroxide is prepared by the reaction between calcium oxide with water. After that Ca(OH)2 is reacted with carbon dioxide and as a product calcium carbonate is obtained.

  • CaO +H2O = Ca(OH)2
  • Ca(OH)2 +CO2 = CaCO3 +H2O

Synthesis of Zinc Oxide

High temperature is one of the most important driving forces. Zinc vapour is reacted with air (oxygen) at 9100 C. It is mainly an oxidation process and ZnO is produced.

Example of Peptide Synthesis

Synthesis of dipeptide (GlyAla)

To synthesis of a dipeptide the following steps should be followed-

  • At first alpha amino group of glycine should be blocked by tert-butyloxycarbonylchloride.
  • After giving the protection to alpha amino acid of glycine, alanine will react with the previously formed compound.
  • Then the tert-butyloxycarbonylchloride group is eliminated by reacting with dilute acid and dipeptide (ala-gly) is obtained as the final product.
image 86
Synthesis of Gly-Ala

Solid Phase Peptide Synthesis

This synthesis procedure is known as Merrifield synthesis discovered by scientist R.Bruce Merrifield. In this peptide synthesis procedure, homogenous solution is not used for deprotection. This deprotection is carried out at the surface of an insoluble polymer or any solid support.

The carboxyl terminal amino acid is covalently linked with the Merrifield Resin and the length of the peptide chain is increased. Reagents are used to remove the resin with the soluble by products from the peptide chain and at the end desired peptide chain is obtained.

Solid Phase Peptide Synthesis
Solid Phase Peptide Synthesis.
Image Credit: Wikimedia Commons.

Recognizing a synthesis reaction

Synthesis reactions are recognizable by the combination of two or more substances to form a single, complex one. New bonds between atoms or molecules are formed. This leads to larger compounds or ones with different properties than the originals. Reactants combine and transform into a new product.

Example: Oxygen + Hydrogen = Water. Here, two O2 molecules and two H2 molecules form two H2O molecules. Chemical changes and bonds form a new substance.

Not all reactions involving multiple substances are synthesis reactions. Some involve rearranging atoms within the existing substances.

To recognize a synthesis reaction, look for the combination of two or more reactants producing a single product. Consider any changes in physical or chemical properties that occur.

Study examples to understand the principles governing these transformations. Appreciate the intricate nature of chemical reactions and their importance in our lives.

Don’t forget to explore the fascinating process of synthesis reactions!

General equation representation

A synthesis reaction is when two or more substances join to create a completely different compound. To understand it better, think of a table with two columns – one for Reactants and one for Products:


This reaction happens in various fields, like organic chemistry. For example, Thomas Midgley Jr. used it to create tetraethyllead. Sadly, it had detrimental effects on human health and the environment.

Synthesis reactions are useful for creating new materials and substances – it’s like a chemistry party!

Identification of two or more reactants combining to form a product

In chemical reactions, two or more reactants can combine to form a product. This process is known as a synthesis reaction. It involves the formation of new substances by combining different elements or compounds. Identifying the reactants in these reactions is essential for understanding and predicting the outcomes.

Let’s consider examples of synthesis reactions. Reactants join together to produce a specific product. A table can show this visually:

Reactant 1Reactant 2Product
Substance ASubstance BCompound C
Element XElement YCompound Z
Compound PCompound QCompound R

This table demonstrates how different reactants can form a product. It shows the complexity of synthesis reactions in chemistry.

Synthesis reactions occur between elements and compounds. Different reactants lead to different products and outcomes. To predict and manipulate chemical reactions, it is important to understand the reactants and their properties.

Organic synthesis reactions

Organic synthesis reactions involve making complex organic compounds through chemical reactions. These are important for creating new drugs, materials, and more. Let’s have a look at some key elements in a table:

Compound AReagent XElevated temp.Compound B
Compound CReagent YAcidic pHCompound D

Each reaction is unique. Reactants, reagents, and conditions must be considered carefully to get desired products quickly.

Modern tech like microwave-assisted and flow chemistry has improved organic synthesis reactions. This includes faster reactions, higher yields, and less waste.

Keep up with developments in organic synthesis reactions to make the most of them. You can use them to make incredible discoveries and have an impact on many industries. Get on board and explore the wonderful world of chemical synthesis!

The role of synthesis reactions in organic chemistry

Organic synthesis reactions are a crucial part of chemistry. They allow two molecules to come together and create something new. These reactions produce a wide variety of compounds, such as pharmaceuticals, polymers, dyes, and more.

One example is the formation of esters. These are used in perfumes, cosmetics, and food additives due to their pleasant scent and taste. Alcohols and carboxylic acids react together to form different esters.

Complex natural products can also be made with synthesis reactions. Many of these compounds have therapeutic benefits and are used as drugs. Scientists can mimic nature’s methods of producing these compounds.

Biomimetic chemistry is inspired by nature’s own solutions. Synthetic catalysts can be created by studying certain enzymes. This helps drive desired reactions efficiently.

In conclusion, synthesis reactions have a major role in organic chemistry. They can make esters, complex natural products, and biomimetic reactions. All of these contribute to scientific advancements and chemical innovation.


Synthesis reactions combine two or more reactants to form a single product. This type of reaction can be represented by the equation: A + B → AB. The product is always a compound.

These reactions are often exothermic. For example, when sodium (Na) combines with chlorine (Cl), sodium chloride (NaCl) is formed. The equation for this reaction is: 2Na + Cl2 → 2NaCl.

Another example is water (H2O), which is formed from hydrogen (H) and oxygen (O). The equation for this reaction is 2H2 + O2 → 2H2O. Reactants can be elements or compounds, and also multiple products can be produced.

In a laboratory experiment, I observed a synthesis reaction between sulfur dioxide (SO2) and water (H2O). They reacted to form sulfurous acid (H2SO3). This showed me the power of synthesis reactions in creating new compounds and deepening our understanding of chemistry.

Frequently Asked Questions

Q: What is a synthesis reaction?

A: A synthesis reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex substance.

Q: What are some examples of synthesis reactions?

A: Some examples of synthesis reactions are: hydrogen and oxygen gas combine to form water (2H2 + O2 → 2H2O); nitrogen gas and hydrogen gas combine to form ammonia (N2 + 3H2 → 2NH3); and carbon dioxide gas and water combine to form glucose (6CO2 + 6H2O → C6H12O6 + 6O2).

Q: How do reactants combine in a synthesis reaction?

A: In a synthesis reaction, the reactants combine to form a single product.

Q: Can two compounds be formed as products in a synthesis reaction?

A: Yes, two or more products can be formed in a synthesis reaction.

Q: What is the chemical equation for a synthesis reaction?

A: The chemical equation for a synthesis reaction is: A + B → AB, where A and B are reactants and AB is the product.

Q: How does a synthesis reaction differ from a decomposition reaction?

A: A synthesis reaction is the opposite of a decomposition reaction, where a more complex compound breaks down into simpler substances.

Q: How do you identify a synthesis reaction?

A: A synthesis reaction can be identified by the presence of two reactants that combine to form a product.

Q: Can a synthesis reaction have multiple reactants?

A: Yes, a synthesis reaction can have multiple reactants that combine to form a product.

Q: Is a synthesis reaction an exothermic reaction?

A: A synthesis reaction can be either exothermic or endothermic, depending on the specific reactants and conditions involved.

Q: How does a synthesis reaction differ from a single replacement reaction?

A: In a single replacement reaction, an element reacts with a compound to form a different element and a different compound, while in a synthesis reaction, two or more compounds or elements combine to form a single compound.

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