Lesson 1: Alkanes, Alkenes & IUPAC Nomenclature
Demonstrating understanding of organic chemical structure, properties, and reactions for NCEA Level 2 Chemistry.
🎯 Ngā Whāinga Akoranga | Learning Intentions
IUPAC naming conventions for alkanes, alkenes, haloalkanes, and branched hydrocarbons up to 8 carbon atoms (C1-C8).
Construct 3D molecular models, draw structural and condensed formulas, and systematically name complex branched hydrocarbons.
🎥 Media Anchor & Pedagogical Scaffold
IUPAC Nomenclature & Hydrocarbon Architecture
Video Clip: GCSE Chemistry — Hydrocarbons, alkanes and the homologous series (2026/27 exams) | Cognito (Runtime: 5m 05s).
🧠 1. Before Viewing (Activate & Predict)
Why is a standardised global naming system (IUPAC) essential for chemists, medical researchers, and chemical engineers worldwide?
👁️ 2. During Viewing (Watch With a Job)
- Define: what is the general formula for alkanes? What does the suffix '-ane' tell you about a molecule's structure?
- Homologous series: the video explains what makes a series 'homologous'. List THREE properties that members of the alkane homologous series share.
- Name: using IUPAC rules from the video, name a straight-chain alkane with 4 carbons and draw its structural formula.
🗣️ 3. After Viewing & Kaiako Move (Process & Apply)
Kaiako Move: Use physical Molymod kit sets to demonstrate structural flexibility of single C-C bonds vs rigid C=C double bonds.
Immediate Task: Complete Section 1 of your Level 2 Chemistry Portfolio: IUPAC Naming & Structural Drawing Mastery Sheet.
⚡ Whakaoho | Do Now: Organic Recall Challenge (10 mins)
Why bother with a long name? A chemist in Hamilton emails a chemist in Berlin the word isopentane. Berlin draws a molecule. Hamilton meant a different one. Both were reasonable readings.
Two minutes, on your own: write down what a chemical name has to do that a common name does not. Then look at 2-methylbutane — longer, uglier, and it can only be drawn one way. Which parts of that name are carrying the information?
📖 Activity 1: Core Reaction Mechanism & Structure Analysis (25 mins)
Name it, then break it (15 min). Working in pairs, name six structures your kaiako gives you. For each, write the three decisions in order: longest chain, position numbers, substituent names. Then swap with another pair and draw from their names only — no peeking at the original. Any molecule you cannot draw unambiguously means the name failed, not you. Find the naming rule that would have saved it.
Alkane or alkene? (10 min). Sort eight formulae into saturated and unsaturated without drawing them. Work out the rule that lets you do it from the formula alone, and write it down. Test it on C₆H₁₂ — and explain why that one is a trap.
📝 Activity 2: Level 2 Chemistry Portfolio Task & Merit/Excellence Scaffolding (20 mins)
Organic Portfolio — Section 1. Submit: (1) six structures named, with the three naming decisions shown for each; (2) three names you were given, drawn correctly; (3) one short paragraph on why C₆H₁₂ could be either a cyclic alkane or an alkene, and what extra information settles it.
🏫 Kaiako Planning & Pedagogy Notes
NCEA Level 2 Alignment: Direct preparation for NCEA Level 2 Chemistry (External) (Demonstrate understanding of the properties of selected organic compounds). Emphasise linking observations and reagents to molecular structure for Merit/Excellence grades.