Final answer:
Chemical reactions are classified as addition, substitution, or elimination based on how reactants combine or transform into products. Substitution can include single or double replacement, while addition and elimination involve combining substances or removing a molecule, respectively. Correct classification requires analysis of reactant and product rearrangements and oxidation number changes.
Step-by-step explanation:
Classification of chemical reactions into addition, substitution, or elimination is based on the process in which reactants are transformed into products. An addition reaction involves two or more substances combining to form a single product. Substitution reactions, also known as replacement or substitution reactions, are reactions in which one substance replaces a part of another. These can be further divided into single replacement and double replacement reactions. Elimination reactions involve the removal of a molecule from a reactant to form a product with a multiple bond or rings.
In terms of nucleophilic reactions, a nucleophilic substitution reaction involves a nucleophile replacing a leaving group, as seen in the nucleophilic substitution bimolecular (SN2) and unimolecular (SN1) mechanisms. Electrophilic addition reactions involve adding an electrophile to a nucleophile, typically in a situation where double or triple bonds are present in the reactants. Electrophilic aromatic substitution reactions bring an electrophile to an aromatic ring. Lastly, redox reactions encompass both oxidation and reduction processes.
To classify a chemical reaction appropriately, one must look at the reactants and the formed products, determine how the atoms and groups have been rearranged, and recognize any changes in oxidation numbers that might indicate a redox process.