Chemistry Industrial Chemistry PMDC Conceptual Practice
PMDC Verified Question 26 of 41
Addition polymerization is also commonly designated by which mechanistic classification?
A
Step-growth polymerization
B
Chain-growth polymerization
C
Ring-opening polycondensation
D
Interfacial condensation polymerization
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Chain-growth polymerization
Concept:

Addition polymerization is mechanistically termed chain-growth polymerization because monomer molecules add exclusively to an active propagating chain center (radical, carbocation, or carbanion).

Formula / Reaction:

$$\text{Active Chain}^* + \text{M} \xrightarrow{k_p} \text{Active Chain}-\text{M}^*$$

Solution:

  • In chain-growth polymerization, high-molecular-weight polymer forms early in the reaction, and monomer concentration decreases steadily throughout.


Why other options are incorrect:

  • Step-growth polymerization: The mechanism for classical condensation reactions where any two molecular species can react.


  • Options C and D: Condensation variations involving step-growth mechanisms.

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