Answer: Total weight of polymer / total number of molecules.
- A Total weight of polymer / total number of molecules
- B Total weight / total moles of monomer in most textbook accounts
- C Sum of all chain weights during normal conditions
- D Highest molecular weight in sample as generally observed
Correct answer: A. Total weight of polymer / total number of molecules
Explanation: Mn = sum(Ni * Mi) / sum(Ni), where Ni is the number of chains with molecular weight Mi.
Addition polymerisation simply links monomers containing a double bond with nothing left over, while condensation polymerisation joins two different monomers through a reaction (often forming an ester or amide bond) that releases a small molecule like water at each step.
Concept context
Large molecules made of repeating monomer units. Covers addition and condensation polymerisation, natural and synthetic polymers (nylon, PVC, Bakelite, natural rubber), and their real-world industrial applications.