Lesson 10: Organic Chemistry Capstone Portfolio Synthesis
Synthesise the unit’s structure, nomenclature, isomerism, reaction and qualitative-analysis learning in a completed portfolio, multi-step challenge and final mastery check.
🎯 Ngā Whāinga Akoranga | Learning Intentions
Integrated understanding of organic chemistry structure, nomenclature, isomerism, reaction mechanisms, and qualitative analysis.
Synthesise complete Level 2 Organic Chemistry Portfolio, present a multi-step synthesis challenge, and complete final mastery revision check.
🎥 Media Anchor & Pedagogical Scaffold
Organic Chemistry Systemic Review
Video Clip: L2 Chemistry 2024 Exam — NCEA Organic Chemistry worked answers (first 14 minutes: capstone review of the full Level 2 organic standard) | MR T's CHEMISTRY (watch 0:00–14:00 of a 44m 06s video).
🧠 1. Before Viewing (Activate & Predict)
How do organic chemical reactions power modern medicine, materials science, and biological life processes?
👁️ 2. During Viewing (Watch With a Job)
- Unit map: as you watch, tick off each topic area from this unit that Mr T addresses — nomenclature, isomers, addition reactions, alcohols, carboxylic acids, polymers, reaction schemes. Which ones appear in the 2024 paper?
- Excellence criteria: write down ONE example from the walkthrough where a student MUST include a mechanism or explanation (not just a product name) to reach Excellence.
- Synthesise: after watching, write a 3–5 sentence paragraph summarising how the topics in this unit connect — using at least three of the seven topic areas from above.
🗣️ 3. After Viewing & Kaiako Move (Process & Apply)
Kaiako Move: Facilitate portfolio review and celebrate student mastery of Level 2 Organic Chemistry.
Immediate Task: Final Level 2 Organic Chemistry Portfolio Submission & Revision Mastery Certificate.
⚡ Whakaoho | Do Now: Organic Recall Challenge (10 mins)
One unknown, everything you know. A colourless liquid: it does not decolourise bromine water, it does not affect litmus, and on warming with acidified dichromate the orange turns green.
Five minutes, on your own, no notes: what functional groups are present and which are ruled out? Name one structure consistent with all three observations — and say honestly whether the evidence pins down a single compound or only a family. Then list which lesson each piece of your reasoning came from — that list is your revision plan for the rest of today.
Kaiako answer key — Do Now. Ruled out: a C=C, because bromine water is unchanged; and a carboxylic acid, because litmus is unchanged. Present: an –OH that can be oxidised — orange to green is Cr(VI) being reduced, and something in the liquid did the reducing. Answer: a primary or secondary alcohol; butan-1-ol and propan-2-ol both fit. The honest half of the question is the second half: the evidence does not pin down a single compound. Acidified dichromate turns green for both primary and secondary alcohols, so a further step — distilling and testing whether the first product is itself an acid — is needed to separate them. A student who names one alcohol and stops has answered; a student who names the family and says what the evidence cannot decide has done the thing this unit has been building towards all along.
If you want the harder version: make the bromine observation positive again — decolourises, no litmus change, dichromate goes green — and the only compound that fits is bifunctional, an alkene-alcohol such as but-3-en-1-ol. That is a legitimate stretch for a strong class, but flag it as beyond the standard: the compound list names single classes, so a bifunctional compound cannot be required of them. The trap in that version is real — "it is an alkene" looks right and is wrong, because an alkene alone leaves dichromate orange, which is the point Lesson 8 presses.
📖 Activity 1: Core Reaction Mechanism & Structure Analysis (25 mins)
Close your own gaps (10 min). Using the list you just made, go back to the two sections of your portfolio you were least sure of and repair them. Not re-read — repair. Rewrite the reasoning so it links structure to observation, the way you practised in Lesson 9.
Full synthesis question (15 min). Work alone and to time — this is the exam condition. The question below requires naming, isomerism, a multi-step conversion and a qualitative identification in one answer.
Integrated question. Compound X has the molecular formula C4H8 and decolourises bromine water in the dark.
- Draw and name two different compounds with the formula C4H8 that would decolourise bromine water.
- One of the two you drew can show cis-trans isomerism and one cannot. Say which, and give both conditions that decide it.
- X is but-1-ene. Draw and name the major and the minor alcohol formed when X reacts with H2O/H+, and justify which is major by relating the structure of X to the product.
- Convert butan-1-ol into butan-1-amine in two steps, and into butanoic acid in one step. Give reagents and conditions for every arrow.
- You are handed but-1-ene, butan-1-ol and butanoic acid in three unlabelled bottles. Give a two-test sequence that identifies all three, stating the observation at each step.
Kaiako answer key — integrated question.
1. Any two of: but-1-ene CH2=CHCH2CH3; but-2-ene CH3CH=CHCH3; 2-methylpropene CH2=C(CH3)2. (Cyclobutane and methylcyclopropane also fit C4H8 but would not decolourise bromine water — a student who names one has answered the formula and ignored the observation, which is worth pointing out rather than simply marking wrong.)
2. But-2-ene shows cis-trans isomerism; but-1-ene and 2-methylpropene cannot. Both conditions must be given: restricted rotation about the C=C, and two different groups on each of the doubly bonded carbons. But-1-ene fails the second condition — its terminal carbon carries two hydrogens.
3. Major butan-2-ol, minor butan-1-ol. The justification must be structural: C1 of but-1-ene already carries two hydrogens and C2 carries one, so the H from the water adds to C1 and the –OH ends up on C2. Naming Markovnikov without relating it to this molecule is not a justification.
4. To the amine: butan-1-ol + PCl5 (or SOCl2, or HCl) → 1-chlorobutane; then excess NH3 in ethanol, sealed tube, heat → butan-1-amine. To the acid: butan-1-ol + acidified Cr2O72− (or MnO4−/H+), heat under reflux → butanoic acid. Reflux is the condition that earns the mark — distilling instead would stop at butanal.
5. Test 1, NaHCO3(aq): effervescence identifies butanoic acid; the other two do nothing. Test 2, bromine water in the dark: orange to colourless identifies but-1-ene; butan-1-ol is unchanged and is therefore the third bottle. Two tests, three identifications — and the third is named by a negative result, which is the habit this whole lesson is built to install.
📝 Activity 2: Level 2 Chemistry Portfolio Task & Merit/Excellence Scaffolding (20 mins)
Organic Portfolio — Section 10 (final). Submit: (1) your opening unknown-identification with full reasoning; (2) the two repaired sections, with a note on what you changed; (3) the completed synthesis question; (4) a one-paragraph self-assessment naming the topic you would revise first and why.
🏫 Kaiako Planning & Pedagogy Notes
Where this sits in the standard. The integrated question deliberately crosses four parts of the standard in one item — naming and drawing, geometric isomerism, a multi-step conversion using the substitution and oxidation lists, and a qualitative identification — because the external paper crosses them too, and students who have only met them one lesson at a time have not yet been tested on the joins.
Exit ticket (3 min, on a slip, collected). Name the one topic from this unit you would revise first, and the specific thing about it you cannot yet do. "All of it" is not an answer.
What to watch for while they work. The Do Now is the diagnostic, not a warm-up: a student who cannot rule out the carboxylic acid from "does not affect litmus" has a Lesson 5 gap, and a student who cannot name a structure has a Lesson 1 gap. Read the slips before Activity 1 and direct the repair work rather than letting students choose.
Differentiation. Support: Let students use their own portfolio during the integrated question, and mark it as an open-book run. The gap being closed is between knowing and retrieving; closing the first one first is fair. Extension: Run the integrated question closed-book and to time, then have students annotate their own script against the answer key and write the one sentence that would have earned the mark they missed.
The error to head off. Students revise what they already know because it feels productive. The exit ticket exists to force the opposite choice, so hold them to naming a specific gap rather than a topic.
Other teaching approach — Portfolio Mastery Course: Exam Synthesis & Multi-Step Synthetic Pathways →