IGCSE Science Practicals Without a Lab: 11 Experiments You Can Run in a Browser (2026)

Ask a hundred IGCSE students in Amman, Dubai or Riyadh how many times they have personally held a burette, and the honest answers cluster around "twice, and someone else did the pouring." Shared labs, classes of thirty, reagents that never arrived, a term of disruption — the reasons vary, the outcome doesn't. And yet Paper 6 / Alternative to Practical still examines the method: which apparatus, which reading, which control, which conclusion. The good news is that the exam has never asked you to be good with your hands. It asks whether you know what should happen and why. That part you can rehearse in a browser.

What lab time actually gives you — and what the exam actually wants

It helps to separate the two, because they overlap less than people assume. A real bench teaches you a handful of things a screen genuinely cannot. But look at what carries the marks in an Alternative to Practical paper and most of it is cognitive, not physical.

Roughly the top half of that right-hand column is knowledge of procedure; the bottom half is data handling. Neither needs a bench. What they need is repetition with feedback — running the same procedure enough times that the order of steps and the reason for each one becomes automatic. That is exactly what a simulation is good at, and exactly what a once-a-term lab session is bad at. If you haven't read it yet, our guide to Paper 6 / Alternative to Practical breaks down how the marks are distributed.

Chemistry: five experiments, and the paper they map to

Chemistry has the densest practical syllabus at IGCSE, and 0620's Paper 6 leans hard on qualitative analysis and on titration technique. Five of the eleven experiments live here.

Titration

You build the apparatus yourself: drag the pipette across, fill it with sodium hydroxide, deliver it into the conical flask, add the indicator. Then you hold the burette tap open and watch the acid run in — swirling the flask as you go — and let go the moment the colour flips at the end-point. Overshoot and you'll see it. Get it right and you score up to three stars, then you take your titre and do the c × V ÷ V calculation to find the unknown concentration, which is where the marks in the written paper actually are.

One deliberate omission: the indicator list contains litmus, thymolphthalein and methyl orange and nothing else. Phenolphthalein is the indicator every textbook video uses, and it is not on the 0620 syllabus — so it isn't in the tool. Learning a reagent the mark scheme never asks for is time you don't have.

Chromatography

Set up the paper, spot the mixture, stand it in the solvent, and see what separates. The mistakes are the teaching. Choose a pen instead of a pencil to draw the baseline and you get extra spots on the chromatogram — the ink runs too. Fill the beaker so the solvent sits above the baseline and your spots wash straight off into the solvent. Both are standard Paper 6 questions ("suggest why the student's chromatogram showed no spots"), and both are far more memorable when you've caused them. R_f values and locating agents appear as Supplement-only content, correctly tiered.

Rates of reaction lab

Marble chips and hydrochloric acid, a gas syringe, and a volume–time graph that draws itself as the run proceeds. You pick the concentration, the temperature and the surface area, then run it — and each completed run leaves a ghost curve behind, so you can overlay a fast run on a slow one. The point that students most often lose a mark on becomes visually obvious: change the rate and the curve gets steeper, but every curve plateaus at the same final volume, because the amount of limiting reactant hasn't changed.

Qualitative analysis and the Chemistry Lab

Qualitative analysis is the single biggest scorer on 0620 Paper 6, and the one that most rewards drilling. In the tool you pour reagents into an unknown salt, watch the precipitate form (and, crucially, watch what happens when you add excess), and name the ion. The Chemistry Lab is the companion piece: name the apparatus on the bench, then choose the right instrument for each measurement. If you want the full reagent-by-reagent map first, read our 0620 qualitative analysis guide, and cross-check what's examinable against the 0620 syllabus breakdown.

Biology: the two practicals 0610 keeps coming back to

Food tests is the classic. Add iodine, Benedict's, biuret, ethanol or DCPIP to a food sample and watch the colour change that identifies the nutrient. It sounds trivial until you're asked, under exam conditions, whether Benedict's needs heating and what "brick-red" actually indicates. Running it ten times in five minutes fixes the table in a way that copying it out never does.

The photosynthesis rate lab is the more interesting one. Pondweed under an inverted funnel, and you count bubbles per minute as you change the light intensity, the carbon dioxide concentration and the temperature. The model behind it is honest: the rate is the minimum of the light and CO₂ terms, multiplied by a temperature factor. So when you crank the light up and the bubble count stops rising, you are looking at a real plateau caused by a different factor — which is precisely the "limiting factor" reasoning the exam wants. (Limiting factors are Supplement content, and the tool tiers them accordingly; the 0610 syllabus guide shows what sits where.)

Physics and Mechanics: four experiments about measurement

Physics Paper 6 is less about reagents and more about precision — reading instruments, plotting honestly, and knowing your sources of error. The four physics-side experiments target exactly that.

• Hooke's law — hang masses on a spring, read the extension, and build the load–extension graph to find the spring constant (and find the limit of proportionality by pushing past it).
• Density lab — weigh an object, then get its volume two ways: from its dimensions, or by displacement. Then decide whether it floats.
• Refraction lab — shine a ray into a glass block, measure the angles of incidence and refraction, calculate the refractive index, then increase the angle until you trap the light with total internal reflection.
• Projectile lab — drag back from a cannon, watch the dotted arc preview update as you aim, and fire through four levels of walls and targets, with ghost trails of your previous shots. This one is Edexcel International A-Level Mechanics rather than IGCSE, but it is the clearest way to see two independent vector equations produce one curve.

Between them these cover the measuring-instrument questions, the graph-drawing questions and the "suggest one source of error" questions that make up most of 0625 Paper 6. The 0625 syllabus guide maps them onto topics.

How to rehearse a practical properly

Opening a simulation and clicking about is not revision. This sequence is:

1. Run it once badly, on purpose
   Use the pen. Fill the solvent too high. Overshoot the end-point. Seeing the failure mode is what makes the exam question about it obvious later.
2. Run it properly, narrating each step
   Out loud or on paper: what am I measuring, with what, and why that instrument? If you can't justify the apparatus, that's the gap.
3. Change exactly one variable
   In the rates lab and the photosynthesis lab, that's the whole skill. Predict the new curve before you run it, then check whether you were right.
4. Do the calculation the exam would ask for
   The titre is not the answer; the concentration is. Take your numbers off the tool and finish the working by hand.
5. Then go and do real Paper 6 questions on that topic
   Simulation builds the mental model; past papers prove it under the mark scheme's wording. Both, in that order.

Being honest about the limits

A browser will not teach you to hold a pipette steady, and if you have lab access you should use it — nothing here replaces a bench. Nor do 11 experiments cover every practical on three syllabuses; there's no electrolysis of a specified salt to a full write-up, no cooling-curve, no distillation. And a simulation is always a model: it shows what should happen, which is a fair description of what Paper 6 asks, but it does not teach you to cope with the run that goes wrong for a reason nobody predicted.

What it does do is remove the two things that actually stop most students revising practicals — access and repetition. You can run a titration eleven times on a Tuesday night. No school in the region will give you that.

Every tool here was built from the official syllabus PDF and verified line-by-line against it, with automated tests pinning the content so it can't drift. Labels are bilingual, English and Arabic, which matters if you learned the science in one language and sit the paper in the other. That's the same standard applied across all 56 interactive tools.

FAQ

If lab time is the thing standing between you and Paper 6 marks, it doesn't have to be. Run the titration until the end-point stops surprising you, overlay three rate curves until the plateau makes sense, and then go and answer the real questions. Open a free account and five of the eleven are yours immediately, or start with the free 3D Cell Explorer and our guide to revising for IGCSE.