In ECET 2026 Chemistry, Polymers and Plastics are a frequent topic. Questions often appear on types of plastics, their preparation, properties, and applications.
📘 Concept Notes
🌐 What are Plastics?
- Plastics are synthetic polymers made from monomers through polymerization.
- They are lightweight, durable, corrosion-resistant, and moldable into different shapes.
- Basic classification: Thermoplastics & Thermosetting plastics.
🔬 Types of Plastics
1️⃣ Thermoplastics
- Soften on heating and harden on cooling.
- Can be reshaped multiple times.
- Examples: Polythene, PVC, Polystyrene, Teflon.
2️⃣ Thermosetting Plastics
- Harden permanently after heating.
- Cannot be remolded or softened again.
- Examples: Bakelite, Urea-formaldehyde resin, Melamine.
⚙️ Polymerization Reactions
- Addition Polymerization:
- Monomers add without elimination of by-products.
- Example:
(Polythene formation)
- Condensation Polymerization:
- Monomers join with elimination of small molecules like
, 
. - Example:
(Polyester formation)
- Monomers join with elimination of small molecules like
🛠 Properties of Plastics
- Light in weight
- Good electrical insulators
- Resistant to corrosion & chemicals
- Easily moldable
- Available in various colors
🔋 Applications of Plastics
- Household Uses: Buckets, bottles, bags
- Electrical Uses: Switches, wires, insulating material
- Industrial Uses: Pipes, packaging, automobile parts
- Medical Uses: Syringes, catheters, disposable items
- Construction: PVC pipes, plastic sheets
🔟 10 Expected MCQs – ECET 2026
Q1. Plastics are mainly made up of:
A) Metals
B) Polymers
C) Alloys
D) Minerals
Q2. Which of the following is a thermoplastic?
A) Bakelite
B) Melamine
C) Polythene
D) Urea-formaldehyde
Q3. Bakelite is an example of:
A) Thermoplastic
B) Thermosetting plastic
C) Elastomer
D) Copolymer
Q4. The reaction by which polythene is formed is:
A) Condensation polymerization
B) Addition polymerization
C) Substitution
D) Hydrolysis
Q5. The monomer of polythene is:
A) Ethylene
B) Styrene
C) Vinyl chloride
D) Formaldehyde
Q6. Which of the following plastics is used for making non-stick cookware?
A) PVC
B) Teflon
C) Polystyrene
D) Bakelite
Q7. Thermosetting plastics can be:
A) Softened again on heating
B) Recycled easily
C) Permanently hardened on heating
D) Melted repeatedly
Q8. The process in which small molecules like or are eliminated is:
A) Addition polymerization
B) Condensation polymerization
C) Hydrolysis
D) Oxidation
Q9. PVC stands for:
A) Polyvinyl Carbonate
B) Polyvinyl Chloride
C) Polyvinyl Compound
D) Polyvinyl Carbide
Q10. Which property makes plastics suitable for electrical insulation?
A) Light weight
B) Chemical resistance
C) Non-conductivity
D) Transparency
✅ Answer Key
| Q.No | Answer |
|---|---|
| Q1 | B |
| Q2 | C |
| Q3 | B |
| Q4 | B |
| Q5 | A |
| Q6 | B |
| Q7 | C |
| Q8 | B |
| Q9 | B |
| Q10 | C |
🧠 Explanations
- Q1 → B: Plastics are polymers.
- Q2 → C: Polythene is a thermoplastic.
- Q3 → B: Bakelite = thermosetting plastic.
- Q4 → B: Polythene formed by addition polymerization.
- Q5 → A: Ethylene is the monomer.
- Q6 → B: Teflon is used for non-stick cookware.
- Q7 → C: Thermosetting plastics cannot be remolded.
- Q8 → B: Condensation polymerization eliminates small molecules.
- Q9 → B: PVC = Polyvinyl Chloride.
- Q10 → C: Plastics are electrical insulators.
🎯 Why Practice Matters
- Plastics are a high-scoring Chemistry topic.
- Questions are direct and often memory-based.
- Practicing MCQs ensures quick marks in ECET 2026.
