Reactions & Chemical Properties of Alkenes Complete Exam Preparation IGCSE Chemistry

Описание: This 45-minute complete revision lecture covers all reactions and chemical properties of alkenes, explained clearly with exam-focused detail, balanced equations, and common past-paper questions.

This video is ideal for IGCSE / O Level / AS Level Chemistry students preparing for theory papers, MCQs, and structured questions.

🧪 Topics Covered in This Video
🔹 1. What Are Alkenes?

General formula: CₙH₂ₙ

Unsaturated hydrocarbons

Presence of C=C double bond

Homologous series characteristics

🔹 2. Addition Reactions of Alkenes (CORE EXAM TOPIC)

✅ Hydrogenation

Alkene + hydrogen → alkane

Catalyst: Nickel (Ni)

Conditions explained

✅ Halogenation

Reaction with bromine / chlorine

Decolourisation of bromine water (test for unsaturation)

✅ Hydrohalogenation

Reaction with HCl / HBr

Formation of halogenoalkanes

✅ Hydration

Reaction with steam

Produces alcohols

Conditions & catalysts included

🔹 3. Combustion of Alkenes

Complete combustion

Incomplete combustion

Energy release comparison with alkanes

🔹 4. Chemical Tests for Alkenes

🧪 Bromine Water Test

Orange → colourless

Why the reaction happens

Examiner wording explained

🔹 5. Polymerisation (High-Frequency Exam Topic)

Addition polymerisation

Monomer → polymer

Poly(ethene) explained

Diagram-based questions

🔹 6. Comparison: Alkenes vs Alkanes
Feature Alkene Alkane
Bond Double (C=C) Single
Reactivity More reactive Less reactive
Test Decolourises bromine water No reaction
🔹 7. Past Paper Questions & Exam Technique

MCQs

Short structured questions

Common mark-scheme phrases

Typical examiner traps

🎓 Learning Outcomes

By the end of this lecture, you will be able to:
✔ Identify and name alkene reactions
✔ Write correct word & symbol equations
✔ State conditions and catalysts accurately
✔ Apply bromine water test confidently
✔ Answer past paper questions with full marks

📚 Helpful For

IGCSE Chemistry students

O Level Chemistry students

AS Level Chemistry beginners

MCQ & theory paper revision

Pre-exam concept consolidation

preparation of alkenes
Reactions of alkenes

Chemical properties of alkenes

Bromine water test chemistry

Addition reactions explained

Polymerisation alkenes

❌ Common Student Mistakes

Forgetting catalysts and conditions

Writing substitution instead of addition

Confusing alkenes with alkanes

Incorrect bromine water explanation

💡 Exam Tip

🔑 If there is a C=C double bond, always think addition reaction.

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