What is a chemical reaction
A chemical reaction is a process that occurs when two or more molecules react or combine to form a new substance. It is not compulsory to combine the molecules, in many cases, a single molecule breaks down to form new substances.
A chemical reaction is also a chemical change where the quality of the element gets changed after the transformation. That transformation can be caused by electricity, heat, or light.
Types of chemical reaction:
A reaction in which two or more reactants combine to form a single product is known as a combination reaction.
General method to represent combination reaction:
X + Y → XY
A combination reaction is also known as a synthesis reaction.
Example: 2Na + Cl2 → 2NaCl
A reaction in which a single compound breaks into two or more simpler compounds is known as a decomposition reaction.
XY → X + Y
A decomposition reaction is just the opposite of a combination reaction.
Example: CaCO3 → CaO + CO2
The reaction in which a compound decomposes due to heating is known as a thermal decomposition reaction.
A chemical reaction in which a more reactive element displaces a less reactive element from its aqueous salt solution.
X + YZ → XZ + Y
It is also called a substitution reaction
Example of displacement reaction: Zn + CuSO4 → ZnSO4 + Cu
Double Displacement Reaction
A chemical reaction in which ions get exchanged between two reactants which form a new compound is called a double displacement reaction.
XY + ZA → XZ + YA
It is also called a metathesis reaction
Example of double displacement reaction:
BaCl2 + Na2SO4 → BaSO4 + 2NaCl