ChemistryChapter 16: Hydrocarbons
Polymerisation (addition, Names)
Ethene many times: poly(ethene), addition polymer, no extra product.
Learning objectives
- Explain polymerisation (addition, names) in simple chemical language.
- Connect 1. repeat unit with 2. issues using equations, observations, or trends where needed.
- Answer a short Federal Board question with the correct terms and a clear reason.
Definition
Ethene many times: poly(ethene), addition polymer, no extra product. Repeat unit drawn from the monomer with the double bond opened. PVC from chloroethene named. Poly(propene) named. Conditions as the book (high P, catalyst names) are exam labels, not a reactor design. Meaning: plastics are long alkanes with optional side groups. Disposal and recycle slogans, not a burn-how-to. Addition: alkene monomers, C=C opens — polyethene, PVC, polystyrene named. Show curly arrows on addition mechanisms; Markovnikov reasoning must precede the product structure.
Formula
C=C opens
Important terms
- POLYMERISATION (ADDITION, NAMES)
- Ethene many times: poly(ethene), addition polymer, no extra product.
- 1. REPEAT UNIT
- Open the double bond, brackets, n.
- 2. ISSUES
- Inert, litter, microplastics named (water chapter).
Relationship
- monomer C=C -> polymer chain
Overview
Draw the unit, then names:
Repeat Unit
Open the double bond, brackets, n. Side groups stay. PTFE from tetrafluoroethene named if in the book. Repeat unit drawn in brackets with n; no small molecule lost.
Examples PE named · PVC named · n large
Issues
Inert, litter, microplastics named (water chapter). Recycle slogan, less single-use slogan. Incineration named as a waste option with pollution slogans — not instructions. Condensation different chapter idea — addition only adds monomers.
Examples Recycle named · Litter · No reactor SOP
WHAT — POLYMERISATION (ADDITION, NAMES)
Ethene many times: poly(ethene), addition polymer, no extra product. Repeat unit drawn from the monomer with the double bond opened. PVC from chloroethene named. Poly(propene) named. Conditions as the book (high P, catalyst names) are exam labels, not a reactor design. Meaning: plastics are long alkanes with optional side groups. Disposal and recycle slogans, not a burn-how-to. Addition: alkene monomers, C=C opens — polyethene, PVC, polystyrene named. Show curly arrows on addition mechanisms; Markovnikov reasoning must precede the product structure.
WHY — Why this topic matters
POLYMERISATION (ADDITION, NAMES) is an independent FBISE learning unit because students must use its definitions, conditions, equations, or trends separately in explanations and calculations.
HOW — How it works
REPEAT UNIT: Open the double bond, brackets, n. Side groups stay. PTFE from tetrafluoroethene named if in the book. Repeat unit drawn in brackets with n; no small molecule lost. Examples: PE named; PVC named; n large. ISSUES: Inert, litter, microplastics named (water chapter). Recycle slogan, less single-use slogan. Incineration named as a waste option with pollution slogans — not instructions. Condensation different chapter idea — addition only adds monomers. Examples: Recycle named; Litter; No reactor SOP. Exam polymer: many ethene molecules add repeat unit -CH2-CH2- name poly(ethene); conditions are names, not a plant
In simple words
Named plastics. No polymer-plant or PVC-factory design.
Key points
- monomer C=C -> polymer chain
- repeat unit
- open C=C
- environment
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Polymerisation (addition, Names)
Sticky Notes · Quick Revision
Core Idea
- Ethene many times: poly(ethene), addition polymer, no extra product. Repeat unit drawn from the monomer with the double bond opened. PVC from chloroethene named. Poly(propene) named. Conditions as the book (high P, catalyst names) are exam labels, not a reactor design. Meaning: plastics are long alkanes with optional side groups. Disposal and recycle slogans, not a burn-how-to. Addition: alkene monomers, C=C opens — polyethene, PVC, polystyrene named. Show curly arrows on addition mechanisms; Markovnikov reasoning must precede the product structure.
1. REPEAT UNIT
- Open the double bond, brackets, n. Side groups stay. PTFE from tetrafluoroethene named if in the book. Repeat unit drawn in brackets with n; no small molecule lost.
- PE named
- PVC named
- n large
2. ISSUES
- Inert, litter, microplastics named (water chapter). Recycle slogan, less single-use slogan. Incineration named as a waste option with pollution slogans — not instructions. Condensation different chapter idea — addition only adds monomers.
- Recycle named
- Litter
- No reactor SOP
Exam Example
- Exam polymer:
- many ethene molecules add
- repeat unit -CH2-CH2-
- name poly(ethene); conditions are names, not a plant
Common Misconceptions
- Do not confuse 1. REPEAT UNIT with 2. ISSUES; state the difference before giving an example.
- Writing only “monomer C=C -> polymer chain” is not enough. Explain what it means in a complete sentence.
FBISE Exam Check
- Explain polymerisation (addition, names), compare its two main parts, and include the correct chemical evidence.
- Named plastics. No polymer-plant or PVC-factory design.
60-second revision
- Ethene many times: poly(ethene), addition polymer, no extra product.
- 1. REPEAT UNIT: Open the double bond, brackets, n.
- 2. ISSUES: Inert, litter, microplastics named (water chapter).
- Exam reminder: Exam polymer: many ethene molecules add repeat unit -CH2-CH2- name poly(ethene); conditions are names, not a plant
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