Differentiate addition polymerization from condensation polymerization.

• A. Addition polymerization forms polymers with loss of small molecules like water.
• B. Addition polymerization forms polymers by adding monomers without byproducts.
• C. Addition polymerization involves monomers with double bonds; condensation polymerization only with single bonds.
• D. Addition polymerization requires catalysts; condensation polymerization does not.

Answer: (B)

Addition polymerization builds the polymer by adding one monomer to the growing chain at a time, and no small molecule is released during the process. The monomers typically have a multiple bond (like a C=C) that opens and forms new C–C bonds as the chain grows, so the mass of the polymer equals the sum of the monomers’ masses minus nothing. This lack of byproducts is the hallmark of addition polymerization.

In contrast, condensation polymerization releases a small molecule (such as water or methanol) whenever a new bond forms between monomer units, so the polymer mass is built up while a byproduct is expelled. That difference in byproduct formation is what distinguishes the two types.