104 Reactions of Alkenes. Alkenes contain the unsaturated CC functional group which characteristically undergo addition reactions. Alkene Reactions Summary Cheat Sheet Organic Chemistry Study Organic Chemistry Organic Chemistry Books Electrophilic Additions to Alkenespdf. . Addition reactions with different reactants Alkenes can react with different types of chemicals during addition reactions. The reaction mechanisms of the addition reactions of alkenes have many similarities to the substitution and elimination reactions. The electrons are more tightly held in a sigma bond between the two. Addition of Bromine and Chlorine to Alkenes An addition reaction also easily occurs between halogens Br2and Cl2 and alkenes. The principal reaction of the alkynes is addition across the triple bond to form alkanes. Addition Reactions to Alkenes - Addition of HXpdf. Step 1 is an acid-base reaction. Addition Reactions to