Detailed Explanation of Types of Chemical Reactions
 |
| Photo by Artem Podrez from Pexels |
A chemical reaction is a process defined by a chemical change in which the reactants (starting materials) differ from the results. Chemical reactions are characterised by the movement of electrons, which results in the creation and breaking of chemical bonds.
The substances that react during a chemical reaction are known as reactants, whereas the substances created during a chemical reaction are known as products. The most prevalent types of Chemical Reactions are explained further below.
Different Types of Chemical Reactions
The five basic types of chemical reactions with examples are as follows:
⦁ Combination reaction
⦁ Decomposition reaction
⦁ Displacement reaction
⦁ Double Displacement reaction
⦁ Precipitation Reaction
Combination Reaction
A combination reaction occurs when two or more reactants combine to generate a single product.
It has the formula A + B → AB.
A synthesis reaction is another name for a combination reaction.
Combination response illustration: 2Na + Cl2 → 2NaCl
Decomposition Reaction
A decomposition reaction occurs when a single chemical breaks down into two or smaller compounds.
It has the formula AB → A + B.
The decomposition reaction is the inverse of the combination reaction.
A decomposition reaction is the electrolysis of water into oxygen and hydrogen gas:
Decomposition reaction illustration: 2 H2O → 2 H2 + O2
A thermal decomposition reaction occurs when a chemical decomposes as a result of heating.
Displacement Reaction
A chemical process occurs when a more reactive element displaces a less reactive element out of its aqueous salt solution.
It has the form A + BC → Y.
It is also called a substitution reaction.
Example of displacement reaction: Zn + CuSO4 → ZnSO4 + Cu
Double Displacement Reaction
A double displacement reaction is a chemical process in which ions are swapped between two reactants to generate a new molecule.
It shows the form of AB + CD → AD + CB
It is also known as a metathesis reaction.
Example of double displacement reaction: A twofold displacement reaction occurs when sodium chloride reacts with silver nitrate to create sodium nitrate and silver chloride.
NaCl(aq) + AgNO3(aq) → NaNO3(aq) + AgCl(s)
Precipitation Reaction
Precipitation reaction refers to a chemical reaction that develops an insoluble product (precipitate; solid). Although the reactants are liquid, the product generated is insoluble and separates as a solid. The chemical equation used to describe a chemical change is appropriate for reactions in solutions,
However, the standard molecular equation has distinct representations for reactions of ionic substances in an aqueous solution (water). A molecular equation may suggest formulae for reactants and products that are not present and entirely omit formulas for ions that are the true reactants and products.
The outcome is an ionic equation if the material in the molecular equation that is indeed present as dissociated ions is stated in the form of their ions.
A precipitation reaction happens when a solution containing dissolved species generates a typically denser solid and falls to the bottom of the reaction vessel.
When two soluble solutions are combined, the most typical precipitation process in an aqueous solution is the production of an insoluble ionic molecule. Consider what occurs when an aqueous NaCl solution is mixed with an aqueous AgNO3 solution.
The first solution consists of hydrated Na and Cl− ions, and the second one contains Ag and NO3− ions.
NaCl(s) → Na (aq) + Cl−(aq)
AgNO3(s) → Ag (aq) + NO3−(aq)
A twofold displacement reaction occurs when these two compounds are combined, resulting in the soluble compound NaNO3 and the insoluble compound AgCl. The Ag and Cl ions mix in the reaction vessel, and a white solid precipitated from the solution. The Na and NO3 ions remain in the solution while the solid precipitates.
The following balanced equation represents the entire double displacement reaction:
NaCl(aq) AgNO3(aq) → AgCl(s) NaNO3(aq)
Example
Is a precipitate formed when aqueous solutions of Pb(NO3)2 and KI are mixed?
Create a balanced equation for the precipitation process when copper(II) iodide and potassium hydroxide aqueous solutions are mixed.
Solution:
You must forecast whether or not a precipitate will develop during a chemical reaction and create a balanced equation for a precipitation process.
Two reactants' identities are revealed to you.
1. When these solutions are combined, a solid precipitate, PbI2, forms:
Pb(NO3)2(aq) KI(aq) → PbI2(s) + 2KNO3(aq)
2. The reaction yields two products: insoluble copper (II) hydroxide and soluble potassium iodide.
CuI2(aq) + 2 KOH(aq) → Cu(OH)2(s) + 2 KI(aq)
There are some more common types of chemical reactions :
Acid-Base Reaction
An acid-base reaction is a sort of double displacement reaction that happens when an acid and a base come into contact. The acid's H ion combines with the base's OH- ion to generate water and an ionic salt:
HA + BOH → H2O + BA
An acid-base reaction is a reaction of hydrobromic acid (HBr) and sodium hydroxide:
HBr + NaOH → NaBr + H2O
Combustion
A combustion reaction is a redox process in which an explosive substance reacts with an oxidiser to produce oxidised products and heat (exothermic reaction). In a combustion reaction, oxygen usually reacts with another chemical to generate carbon dioxide and water. The burning of naphthalene is an example of a combustion reaction:
C10H8 12 O2 → 10 CO2 4 H2O
Isomerisation
The structural arrangement of chemical changes during an isomerisation reaction, while its net atomic composition stays unchanged.
Hydrolysis Reaction
Water is used in the hydrolysis process. A hydrolysis process takes the following general form:
X-(aq) + H2O(l) ↔ HX(aq) + OH-(aq)
Conclusion
There are hundreds of different types of chemical reactions. If you are asked to list the principal four, five, or six types of chemical reactions, this is how they are classified. Direct combination, analytical reaction, single displacement, and double displacement are the four primary types of reactions. There are five main types of reactions; these are the first four, followed by acid-base or redox reactions, Isomerization, Hydrolysis Reaction and Combustion.