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A synthesis reaction , also known as a direct combination reaction , is a type of chemical response in which two or more simple substances combine to form a more complex product. The reactants can be elements or compounds, while the product is always a compound.
Synthesis reaction definition
Analyzing its etymology, the word “reaction” derives from Latin and is composed of the prefix ” re “, which means “backwards”, and ” actio “, from the verb ” agere “, which translates as “to carry out” or “to carry just”. The word “synthesis”, for its part, comes from the Greek ” synthesis “, which translates “composition that is formed from the sum of parts”. The name obtained by adding the prefix » syn », which can be translated as »with» and » thesis », a synonym for conclusion. Having said this, it can be said that the synthesis reaction is one in which two different atoms or molecules interact to form another compound or molecule .
The synthesis reaction is also known as a combination reaction, and can be defined as a process in which two or more chemical substances combine to form a different compound. Generally, the substances that produce the synthesis reaction are called reagents , and what is obtained from them, product .
Synthesis reaction in different substances
Synthesis reactions can occur both between organic and inorganic substances. In the case of organic substances, synthesis reactions take place both in nature and in laboratories. All living organisms absorb nutrients and substances that are combined in a biological process, creating all the compounds that make them up. Laboratories can also carry out this type of reaction and, in fact, they are the basis of the pharmaceutical, cosmetic and food industries. This is because there is a high demand for highly useful natural substances that are scarce in nature.
For its part, the synthesis reaction in inorganic elements is important in the industrial sector. In this way, substances are obtained that do not exist in the natural world. For example, steel, which is the synthesis of iron and carbon; or bronze, which is the synthesis of copper, tin and sometimes nickel.
How to recognize a synthesis reaction?
A synthesis reaction can be recognized when two or more elements combine to form a compound. Another important characteristic of synthesis reactions is that the number of molecules that are produced is less than that of the reactants.
In addition, the synthesis reactions are exothermic , that is to say that, when the new bond is formed between the molecules during the reaction, heat energy is released.
Classification of synthesis reactions
Synthesis reactions can be classified into:
- Partial synthesis: if the reagents are elemental and compound substances, or only compounds, the synthesis is partial. For example, the synthesis of calcium hydroxide: CaO(s) + H 2 O (l) → Ca (HO) 2 (aq).
- Total synthesis: when all the reagents are elemental substances. An example of this is the synthesis of water: 2 H 2 (g) + O 2 (g) → 2 H 2 O (g).
Examples of synthesis reactions
There are countless examples of synthesis reactions. Some of the most common are:
- Water: 2 H 2 (g) + O 2 (g) → 2 H 2 O (g)
- Carbon dioxide: 2CO (g) + O 2 (g) → 2CO 2 (g)
- Potassium Chloride: 2 K (s) + Cl 2 (g) → 2 KCl (s)
- Ammonia: 3 H 2 (g) + N 2 (g) → 2 NH 3 (g)
- Aluminum oxide: 4 Al (s) + 3 O 2 (g) → 2 Al 2 O 3 (s)
- Iron Sulfide: 8 Fe + 8 S → 8 FeS
- Magnesium oxide: 2?g + O 2 → 2?gO
- Sulfuric acid: SO 2 (g) + H 2 O(l) → H 2 SO 3 (aq)
Sources
- Brown L. theodore, LeMay, Eugene H Jr., Bursten E. Bruce, and Burdge R Julia. (2004). Chemistry the Central Science . Mexico: EARSON.
- Burns, R. (2003). Fundamentals of Chemistry .
- Carpi, A. & Dingle, A. (2003). Chemical Reactions . Vision learning. 1( 6 ).
