replacement reaction

In chemistry, a substitution reaction is a type of reaction where an atom, ion, or group of atoms within a molecule is replaced by another atom, ion, or group. This process is fundamental to organic chemistry, allowing for the transformation of one organic compound into many others by swapping out different chemical groups.1

Substitution reactions are broadly categorized into three main types based on the nature of the substituent:
* Nucleophilic substitution: Occurs when an electron-rich substituent (a nucleophile) bonds with the substrate, providing the electron pair for the new bond.1
* Electrophilic substitution: Happens when the substituent is electron-deficient and the substrate provides the electron pair for bonding.1
* Radical substitution: Involves reactions between free radicals and substrates.1

An example of a substitution reaction is when the chlorine atom in chloromethane is replaced by a hydroxide ion to form methanol.1