Decomposition brought about by heat is known as thermal decomposition. What is the difference between thermal dissociation and thermal decomposition?

Thermal dissociation and thermal decomposition are related processes, but they involve different types of chemical reactions and have distinct characteristics:

Thermal Decomposition:

Thermal decomposition refers to a chemical reaction in which a single compound breaks down into two or more simpler substances when heated. This process typically involves the breaking of chemical bonds within the compound, leading to the formation of new compounds or elements.
It is a more general term and can encompass various types of reactions, such as pyrolysis, combustion, and decomposition of salts.
Example: The thermal decomposition of calcium carbonate (CaCO3) into calcium oxide (CaO) and carbon dioxide (CO2) when heated is a common example of thermal decomposition.
CaCO3(s) → CaO(s) + CO2(g)
Thermal Dissociation:

Thermal dissociation specifically refers to the process in which a compound undergoes a reversible breakdown into its constituent ions or simpler molecular fragments when heated. In this process, the compound dissociates into its individual components without necessarily forming entirely new chemical species.
It usually occurs in ionic compounds or molecules with covalent bonds that can break into ions or radicals.
Example: The thermal dissociation of hydrogen chloride (HCl) gas into hydrogen ions (H⁺) and chloride ions (Cl⁻) when heated is an example of thermal dissociation.
HCl(g) ⇌ H⁺(g) + Cl⁻(g)
In summary, thermal decomposition is a broader term that encompasses various types of chemical reactions that occur upon heating, leading to the breakdown of compounds into simpler substances. Thermal dissociation, on the other hand, specifically refers to the dissociation of a compound into its constituent ions or molecular fragments when heated, often in the context of ionic or molecular species.