Reversible, Redox, and Thermal Dissociation Reactions

 Reversible Reactions  

- Definition: Reactions that can proceed in both directions from reactants to products and back again.  

- Representation: Shown using a double half‑headed arrow (⇌).  

- Key Insight: At equilibrium, both forward and backward reactions occur simultaneously.  

Oxidation/Reduction (Redox) Reactions  

- Definition: A reaction in which oxidation and reduction occur simultaneously.  

- Origin of Name: “Red” stands for reduction, “Ox” stands for oxidation.  

Oxidation:  

- Addition of oxygen to a substance, or  

- Removal of hydrogen from a substance.  

Reduction:  

- Addition of hydrogen to a substance, or  

- Removal of oxygen from a substance.  

Agents:  

- Oxidising Agent: Transfers oxygen to another substance or removes hydrogen from it.  

- Reducing Agent: Transfers hydrogen to another substance or removes oxygen from it.  

Thermal Dissociation  

- Definition: Splitting of a compound into two or more simpler compounds, molecules, or elements upon application of heat.  

- Difference from Thermal Decomposition:  

  - Thermal decomposition is irreversible.  

  - Thermal dissociation is reversible, meaning the products can recombine to form the original compound.