1. Combustion Reactions
Definition
Combustion involves a highly exothermic reaction between a fuel and an oxidizing agent (typically oxygen), producing heat and light, usually in the form of a flame.
The products of combustion are often water and carbon dioxide.
Example
Methane Combustion: CH4 + 2O2 → CO2 + 2H2OCH4 + 2O2 → CO2 + 2H2O
2. Acid-Base Reactions
Definition
An acid-base reaction involves the exchange of a proton (H+) between an acid (proton donor) and a base (proton acceptor).
This type of reaction usually results in the formation of water and a salt.
Example
Neutralization of HCl by NaOH: HCl + NaOH → H2O + NaClHCl + NaOH → H2O + NaCl
3. Redox Reactions
Definition
Redox (reduction-oxidation) reactions encompass the transfer of electrons between species, where one species is oxidized (loses electrons) and the other is reduced (gains electrons).
These reactions are fundamental to energy production, corrosion, and biological metabolism.
Example
Reaction of Hydrogen Peroxide with Potassium Permanganate: 2KMnO4 + 5H2O2 + 3H2SO4 → K2SO4 + 2MnSO4 + 8H2O + 5O2
4. Esterification Reactions
Definition
Esterification is the reaction of an alcohol with a carboxylic acid to produce an ester and water. This process is often acid-catalyzed.
Example
Formation of Ethyl Acetate: CH3COOH + CH3CH2OH → CH3COOCH2CH3 + H2O
5. Substitution Reactions
Definition
Substitution reactions involve the replacement of one functional group in a molecule with another.
These can be nucleophilic or electrophilic, based on the nature of the substituting reagent.
Example
Chlorination of Methane: CH4 + Cl2 → CH3Cl + HClCH4+ Cl2 → CH3Cl + HCl
6. Addition Reactions
Definition
Addition reactions occur when two or more molecules combine to form a single product.
These reactions are common with unsaturated compounds, like alkenes and alkynes.
Example
Hydrogenation of Ethene: CH2=CH2 + H2 → CH3−CH3CH2=CH2 + H2 → CH3−CH3 (using a metal catalyst, such as Pt)