Cambridge IGCSE Chemistry 0620/62 is the May/June 2026 Paper 6 (Alternative to Practical), variant 2. It lasts 1 hour, is worth 40 marks and is sat by Core and Extended candidates whose school enters them for the written alternative rather than Paper 5. It had four compulsory questions, and the second, on a rate experiment with ethanoic acid, carried 19 marks. This guide goes through the paper question by question and shows what the official mark scheme gave marks for. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all six 0620 papers from this series, see IGCSE Chemistry 0620 May/June 2026 past papers: what came up and how it was marked.

Paper 6 shared three of its four contexts with Paper 5, so its Questions 2, 3 and 4 match Paper 5’s Questions 1, 2 and 3. The 0620 Paper 52 guide shows how the same experiment was marked when students did it themselves.

0620/62 at a glance

Question	Topic	Marks	Main command word
1	Fractional distillation of three alkanes	8	Name, state
2	Rate: volume of gas from ethanoic acid and sodium hydrogencarbonate at five dilutions	19	Complete, plot, state
3	Tests on solid C and solution D (ammonium bromide)	7	Identify, record expected observations
4	Planning: obtaining tin metal from the ore cassiterite	6	Describe
	Total	40

Question-by-question walkthrough

Question 1: fractional distillation of alkanes (8 marks)

A mixture of pentane (boiling point 36 °C), hexane (69 °C) and undecane (196 °C) was separated using a flask, a thermometer and a water-cooled condenser.

• Naming apparatus A and B (2 marks): A is the condenser and B is a beaker. “Liebig”, “cooling tube”, “water jacket” and “delivery tube” were ignored for A, so name it as a condenser. For B, flask, trough or tub were rejected. Both correct but swapped scored one.
• Where to heat (1 mark): an arrow anywhere under the beaker on the left (a drawn heating device was also accepted).
• Why not a Bunsen burner (1 mark): the alkanes are flammable and could catch fire. Answers about the apparatus burning, overheating, explosions or keeping a steady temperature were ignored.
• Where cooling water enters (1 mark): a W by the bottom inlet of the condenser. A W anywhere else, including inside the condenser, was rejected.
• Which alkane collects first (1 mark): pentane, because it has the lowest boiling point. Alkane and reason together earned the mark.
• What is left in the flask (2 marks): undecane (1), because its boiling point is above 100 °C, the temperature at which water boils, so it never gets hot enough to boil (1). The second mark needed undecane first. “It has the highest boiling point” on its own was ignored, because it doesn’t explain why the undecane never boils.

Question 2: rate of reaction with dilution (19 marks)

The same experiment as Paper 5 Question 1: 1 g of sodium hydrogencarbonate added to 10.0 cm³ of dilute ethanoic acid with 100, 90, 80, 70 or 60 cm³ of distilled water, collecting gas for 75 seconds. You read the gas volumes from measuring cylinder diagrams.

• Completing the table (3 marks): one mark for all ten liquid volumes (acid 10.0, water 100, 90, 80, 70, 60); one for the five cylinder readings, 10, 16, 27, 46 and 82 cm³; and one for the right precision, acid to one decimal place and water and gas volumes as whole numbers.
• Graph (4 marks): a linear y-axis scale with the points over halfway up (1), all five points correct (2, or 1 for four), and a best-fit line (1). With these results the line should be a curve passing within a small square of every point. Curves made of straight sections, separate curves between neighbouring points and multiple lines were rejected.
• Mean rate in Experiment 3 (2 marks): 27 ÷ 75 = 0.36 (1) and the unit cm³/s (1, a standalone mark). ml or cc were accepted for cm³.
• Highest mean rate (1 mark): Experiment 5, with 60 cm³ of water.
• Reading the graph at 77 cm³ of water (3 marks): construction lines from 77 on the x-axis to the line and across to the y-axis (1), the correct value within half a small square (1), and the unit cm³ (1, standalone). The mark scheme gives no single numerical answer here, because the value comes from your own curve.
• Why a 10 cm³ measuring cylinder rather than a 50 cm³ one (1 mark): more accurate. “Faster” was ignored.
• Advantage of a volumetric pipette (1 mark): more accurate. Speed, ease of use and “fixed volume” comments were ignored.
• Effect of gas escaping before the stopper goes in (1 mark): less gas is collected. Saying the rate of reaction changes was rejected.
• Where most gas escapes (2 marks): Experiment 5 (1), because gas is made fastest there, so more is produced before the stopper is back in (1). The explanation had to be about speed and only scored with the right experiment. “Highest concentration” alone was ignored.
• Line for 20.0 cm³ of acid (1 mark): sketched above the plotted line without touching it at any point.

Question 3: tests on solid C and solution D (7 marks)

You were given the observations for solid C: a lilac flame, condensation when heated, a green precipitate with sodium hydroxide that dissolved in excess to give a dark green solution, and a white precipitate with acidified barium nitrate. Solution D was named as aqueous ammonium bromide.

• Conclusion from the condensation (1 mark): solid C is hydrated, or contains water of crystallisation. “Water” alone, “wet” or “damp” were ignored.
• The three ions in C (3 marks): chromium(III), potassium and sulfate. A wrong oxidation state for chromium or any extra ion was rejected; a wrong combined formula with two correct ions scored 2.
• Expected result with sodium hydroxide (1 mark): no change or no precipitate. “Ammonia given off” and “bubbling” were ignored, but anything implying a visible change was rejected.
• Warming and testing the gas (1 mark): damp red litmus turns blue. A second positive gas test was rejected.
• Nitric acid then silver nitrate (1 mark): a cream precipitate.

Question 4: planning to obtain tin from cassiterite (6 marks)

Identical to Paper 5 Question 3. Tin lies between copper and iron in reactivity, and cassiterite contains tin(IV) oxide, which is insoluble in water but reacts with dilute acids. You described how to get tin metal from a large lump of the ore.

Four routes scored, each with seven marking points and one mark per point up to six:

• Every route started with crushing or grinding the ore and naming how (pestle and mortar, or hammer).
• Reducing the solid: add a more reactive element or reducing agent, name it (carbon or coke, iron, zinc, aluminium, magnesium, carbon monoxide or hydrogen), heat it in a crucible or evaporating basin, and tin is displaced.
• Displacement from solution: add a dilute acid, name a strong one (hydrochloric, sulfuric or nitric), add a more reactive metal, name it (for example iron, zinc or magnesium), and tin is displaced.
• Electrolysis of the solution: dissolve in a named dilute strong acid, electrolyse with named inert electrodes (carbon or platinum), tin forms at the cathode.
• Electrolysis of the molten oxide: heat until molten, electrolyse with inert electrodes, tin forms at the cathode.

Concentrated acids were rejected, a weak acid such as ethanoic got the “add acid” mark only, and calcium or anything more reactive was rejected as the displacing metal. Naming the metal does not also earn the “more reactive metal” point, so state both. Washing, drying and crystallising steps were ignored.

Where the marks are on 0620/62

• Graph and data work in Question 2 carried 13 marks: the table (3), plotting (4), the rate calculation with unit (2) and the graph reading with working and unit (3), plus the sketch line (1).
• “State” questions carried 8 marks: 1(d), 1(e), 2(c)(ii), 2(e)(i), 2(e)(ii), 2(f)(i) and 3(a).
• Ion identification and expected observations carried 6 marks (3(b) to 3(e)). The qualitative analysis notes printed at the back cover all of them.
• Labelling and drawing on the distillation diagram carried 4 marks: naming A and B (2), the heating arrow (1) and the water inlet (1).
• “Explain” and “deduce” parts carried 3 marks: the Bunsen burner question (1) and the experiment where most gas escapes (2).
• The 6-mark tin plan is the biggest single answer. Six separate, specific steps is the target.

How to self-mark 0620/62 with the mark scheme

1. Learn the abbreviations first. A semicolon separates marking points, a slash shows alternatives, A means accept, R means reject, I means ignore, ecf means error carried forward and AW means alternative wording.
2. Check your cylinder readings against 10, 16, 27, 46 and 82. One wrong reading loses that table mark, and it carries into your graph.
3. Mark precision separately. Acid to one decimal place, water and gas as whole numbers: this is its own mark in 2(a).
4. Be strict with the curve. If your line is a set of straight segments or misses a point by more than a small square, don’t give yourself the mark.
5. Give the unit marks separately. cm³/s in 2(c)(i) and cm³ in 2(d) are standalone marks.
6. Watch for answers on the ignore list. “Highest boiling point” in 1(e), “water” alone in 3(a) and “highest concentration” in 2(f)(ii) all scored nothing.
7. Mark the tin plan against one route, tick each point you made and stop at six.

Sit 0620/62 as a timed mock

The paper allows 60 minutes for 40 marks, about one and a half minutes per mark. A workable plan:

Block	Marks	Time
Question 1	8	11 minutes
Question 2	19	27 minutes
Question 3	7	9 minutes
Question 4	6	9 minutes
Check units, decimal places and the graph	–	4 minutes

Draw the graph in pencil with a sharp point, and plan the tin method as six numbered steps before writing.

Other May/June 2026 0620 papers

• 0620 Paper 12 (Core Multiple Choice)
• 0620 Paper 22 (Extended Multiple Choice)
• 0620 Paper 32 (Core Theory)
• 0620 Paper 42 (Extended Theory)
• 0620 Paper 52 (Practical Test)

Practise and download

• Download 0620/62 and its mark scheme on the Learning Portal →
• All 0620 May/June 2026 papers: overview and marking patterns
• Try a free IGCSE Chemistry quiz

Need help with a 0620 topic? Book a free trial lesson with an IGCSE Chemistry tutor →

Frequently asked questions

What topics were on 0620 Paper 62 May/June 2026? +

Four questions: fractional distillation of pentane, hexane and undecane (8 marks); the volume of gas made in 75 seconds when dilute ethanoic acid reacts with sodium hydrogencarbonate at five dilutions (19 marks); tests on solid C and aqueous ammonium bromide (7 marks); and a 6-mark plan for getting tin from the ore cassiterite.

How many marks is 0620/62 and how long is it? +

It is out of 40 marks and lasts 1 hour. Question 2, the rate experiment, is the biggest at 19 marks.

What were the gas volumes and the mean rate on 0620/62? +

The measuring cylinder readings were 10, 16, 27, 46 and 82 cm³ for Experiments 1 to 5. The mean rate in Experiment 3 was 27 ÷ 75 = 0.36 cm³/s, with the unit worth a separate mark.

Why was undecane left in the flask on 0620/62? +

Undecane boils at 196 °C, above the boiling point of water at 100 °C, so heating the flask in water can never get it hot enough to boil. Saying only that it has the highest boiling point was ignored.

Is 0620/62 the same as 0620/52? +

They share three contexts: the ethanoic acid rate experiment, the tests on solid C and solution D, and the tin extraction plan. Paper 6 adds a fractional distillation question and gives you measuring cylinder diagrams and observations to analyse instead of asking you to do the experiments.

Where can I download 0620/62 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge IGCSE Chemistry 0620 past papers page.

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