What I Keep, Fix, and Skip in My IGCSE Chem Lessons

Week 5 of Lent term, my Year 10 International GCSE set hit “Acids, bases, and salts”. Half the class used “base” and “alkali” interchangeably, and one worksheet I’d grabbed treated 1 mol gas at room conditions as 24.5 dm³. That’s the kind of tiny mismatch that multiplies. British IGCSE (Cambridge or Pearson Edexcel International GCSE) expects clarity on Core vs Extended content, steady use of Mr and Ar, gas volumes at 24 dm³ at r.t.p., and very specific qualitative tests (chloride with silver nitrate, sulfates with barium nitrate, ammonia test paper, etc.).

On-topic isn’t enough. I’ve binned gorgeous slides that used “molar mass” all lesson, or skipped ionic equations in salt prep. The pathway also leans on command words—define, describe, explain, calculate—so I try to mirror that cadence in class tasks. When I sanity-check new materials, I scan for Core/Extended tags, correct gas laws shortcuts, and the right salts prep routes (insoluble base + acid vs precipitation). If I’m hunting for something to adapt, I start in the science community and then tag it by topic in my planner from the library.

Last Thursday my Year 11 set 2 came in waving a pretty “revision sheet” they’d found. It used SF to 4 d.p. on a 2-mark moles question and called Mr “molar mass” throughout. Nice layout, wrong pathway accents. Now I run a quick five-minute audit before I photocopy anything:

• Vocabulary pass: Mr/Ar used consistently; state symbols sensible (aq, not “(l)” for solutions); “alkali” reserved for soluble bases.
• Rigor check: 24 dm³ at r.t.p. used; significant figures match data; ionic equations appear where expected.
• Core/Extended flags: Extended-only steps (e.g., multi-step stoichiometry) are marked so I can differentiate.
• Command words: tasks begin with define/describe/explain/calculate, and marks hint at depth.
• Assessment style: short parts building to a multi-mark reasoned finish, not a single sprawling prompt.

If it passes, I drop it into my week plan and, if I need a gap filled, I’ll build a quick quiz or starter to match the same terms and command words in minutes. ClassPods keeps those variants side by side so I can toggle Core and Extended without retyping.

Two Mondays ago, my Year 11 Extended group were rusty on stoichiometry but desperate for “one clean run” at titration calculations. Here’s the lesson that stuck and still matches British IGCSE expectations.

• Objective (2 min): Calculate unknown concentration from titration data and write the balanced ionic equation for a strong acid–strong alkali.
• Starter (6 min): Mini-retrieval: units match-up (mol, dm³, cm³); quick Mr for NaOH and HCl; 3 one-mark moles-from-concentration warmups.
• Main (32 min): Worked example on the board: 25.0 cm³ of 0.100 mol/dm³ HCl neutralises 20.0 cm³ NaOH. Find c(NaOH). Steps: convert cm³→dm³; n(HCl)=0.100×0.0250=0.00250 mol; 1:1 ratio so n(NaOH)=0.00250; c=n/V=0.00250/0.0200=0.125 mol/dm³. Pair practice: one 1:1, one 2:1 (e.g., H2SO4 with NaOH) for Extended.
• Formative check (12 min): Three short parts: (a) new dataset; (b) round to appropriate SF; (c) write the balanced ionic equation. Swap-mark with my AO codes.
• Plenary (8 min): “Explain” prompt: why we rinse burette with solution, not water; collect two lines using correct vocabulary.

I saved the exit check and variants together so next time I can reshuffle parts A–C without rewriting; you can set up the same pack in one go. ClassPods makes the Core/Extended branching less fiddly than my old folder maze.

Last mock season, my Year 10 Core group froze on a 6-marker about testing for sulfate ions. My marking life got saner when I switched to a simple AO-aligned rubric they can see before they start. Steal this, paste it into your booklet, and tweak topic words.

IGCSE Chemistry 6-mark rubric (Core/Extended)

• AO1 Knowledge (0–2): 0 = no relevant facts. 1 = recalls some key facts (e.g., reagent named). 2 = accurate facts with correct terms (e.g., barium nitrate; white precipitate if sulfate).
• AO2 Application/Analysis (0–2): 0 = no link to scenario. 1 = partial sequence (mix, observe) or incomplete reasoning. 2 = correct procedure/order and links observation to conclusion.
• AO3 Experimental skills (0–2): 0 = absent. 1 = some control/safety (add acid first). 2 = clear steps, appropriate controls, and waste/safety named.

Question stems: “Describe the procedure to test for…”, “Explain why … forms a white precipitate with …”, “Calculate … then explain your choice of indicator”. Feedback codes: VOC (vocab), BAL-EQ (equations), SF (sig figs), PROC (procedure order). If you want a blank, I keep a make-your-own slot ready to duplicate so each topic gets its own version.

Last December, a new student joined my Year 10 from Madrid and another from Dubai, both bright, both translating mid-sentence. I now build dual-language anchors for the non-negotiables: “relative formula mass (Mr)”, “alkali (soluble base)”, “precipitate (solid formed)”. A tiny glossary box on each sheet plus a sentence frame (“Because … therefore …”) buys them time while we work examples aloud.

Pacing-wise, I plan Core to mastery with one Extension fork per lesson. Extended students get the fork every time; Core students hit it on Fridays. My homework runs as paired sets: Set A mirrors Core; Set B adds the Extended push (ionic equations, multi-step stoichiometry). I keep both versions stored under the same week tag in ClassPods so I can assign the right one quickly and leave comments after a spot-check. If cost is part of your department chat, the options are spelled out on the pricing page and were easier to justify than the paper I was burning each term.