Chemistry » Organic Molecules » Addition, Elimination And Substitution Reactions

We will study three main types of reactions – addition, elimination and substitution.

• An addition reaction occurs when two or more reactants combine to form a single product. This product will contain all the atoms that were present in the reactants. Addition reactions occur with unsaturated compounds.

The general equation for an addition reaction: $$\text{A}+\text{B}$$ $$\to$$ $$\text{C}$$

Notice that C is the final product with no A or B remaining as a residue.

• An elimination reaction occurs when a reactant is broken up into two products. Elimination reactions occur with saturated compounds.

The general equation for an elimination reaction: $$\text{A}$$ $$\to$$ $$\text{B}+\text{C}$$

• A substitution reaction occurs when an exchange of elements in the reactants takes place. The initial reactants are transformed or swopped around to give a final product.

The general equation for a substitution reaction: $$\text{AB} + \text{CD}$$ $$\to$$ $$\text{AD} + \text{BC}$$

Some specific examples of these reactions are given in the following pages.