Cambridge IGCSE Chemistry 0620/52 is the May/June 2026 Paper 5 (Practical Test), variant 2. It lasts 1 hour 15 minutes, is worth 40 marks and is sat by Core and Extended candidates whose school enters them for the practical rather than Paper 6. It had three compulsory questions, and the first, a rate experiment you carry out yourself, was worth 20 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 5 and Paper 6 shared all three of this paper’s contexts. If your school entered you for the written alternative, read the 0620 Paper 62 guide too: it uses a printed set of results for the same rate experiment.

0620/52 at a glance

Question	Topic	Marks	Main command word
1	Rate: volume of gas from ethanoic acid and sodium hydrogencarbonate at five dilutions	20	Complete, plot, state
2	Tests on solid C and solution D: identifying five ions	14	Record observations, identify
3	Planning: obtaining tin metal from the ore cassiterite	6	Describe
	Total	40

Question-by-question walkthrough

Question 1: rate of reaction with dilution (20 marks)

You added 1 g of sodium hydrogencarbonate to 10.0 cm³ of dilute ethanoic acid mixed with 100, 90, 80, 70 and then 60 cm³ of distilled water, and collected the gas over water in an inverted measuring cylinder for 75 seconds.

• Completing the results table (4 marks): one mark for recording every acid volume as 10.0 (one decimal place) and every water volume as a whole number; one for the correct water volumes (100, 90, 80, 70, 60); one for five gas volumes, all above zero; and one for a larger gas volume in Experiment 5 than in Experiment 1. Less water means a more concentrated acid, so your own results had to show the trend.
• Graph (4 marks): a linear scale on the y-axis with the points reaching above halfway up the grid (1), all five points plotted correctly within half a small square (2, or 1 for four correct), and a line of best fit (1). The line could be straight or curved, whichever fits your points, but it had to ignore anomalous points. Dot-to-dot lines, several lines and S-shaped (sigmoidal) lines were rejected. Points on a non-linear part of the scale scored nothing.
• Mean rate in Experiment 3 (2 marks): your Experiment 3 gas volume divided by 75, correctly rounded to two or more significant figures (1). The unit cm³/s (or cm³ s⁻¹) was a separate mark; ml or cc were accepted for cm³.
• Experiment with the highest mean rate (1 mark): Experiment 5, the one with 60 cm³ of water. If your results pointed elsewhere, error carried forward applied.
• Reading the graph at 77 cm³ of water (3 marks): one for showing the construction lines from 77 on the x-axis up to your line and across to the y-axis (at minimum a mark on the line or on both axes), one for the correct reading within half a small square, and one for the unit, cm³. Working drawn to a random point that is not on your line lost the ecf.
• Why a 10 cm³ measuring cylinder rather than a 50 cm³ one (1 mark): it is more accurate. Precise or more exact were accepted; “faster” was ignored.
• Advantage of a 10 cm³ volumetric pipette (1 mark): again, more accurate. Comments on speed, ease of use or adding dropwise were ignored.
• Effect of gas escaping before the stopper goes in (1 mark): the volume collected is smaller. Answers about the rate of reaction changing were rejected.
• Experiment where most gas escapes (2 marks): Experiment 5, because gas is made fastest there, so more is produced before the stopper is replaced. The explanation mark needed the correct experiment first, and it had to be about the speed of gas production. “Highest concentration” on its own was ignored, as was “it makes the most gas” without reference to the time.
• Sketching the line for 20.0 cm³ of acid (1 mark): your sketched line had to sit above the plotted line and never touch it. It did not need the same shape.

Question 2: tests on solid C and solution D (14 marks)

• Flame test on C (1 mark): lilac. Pink or purple were allowed, and the examiner checked your result against the supervisor’s.
• Heating C (2 marks): condensation at the top of the tube, or steam given off (1); and the solid melting, becoming a liquid or dissolving, or turning black or green (1).
• Aqueous sodium hydroxide, then excess (2 marks): a green precipitate (1) that dissolves in excess to give a green solution (1). The second mark needed some sign that a solid had formed first. Extra wrong observations, such as “turns brown” or “fizzes”, were rejected.
• Dilute nitric acid then barium nitrate (1 mark): a white precipitate.
• The three ions in C (3 marks): chromium(III), potassium and sulfate, one mark each. A name takes precedence over a formula. A wrong oxidation state for chromium was rejected, and so was any extra ion. A wrong combined formula that still contained two correct ions scored 2; symbols such as Cr or SO4 standing alone scored nothing.
• Sodium hydroxide added to D (1 mark): no visible change, no precipitate, colourless solution. Anything implying a change, such as fizzing, was rejected.
• Warming and testing the gas (1 mark): damp red litmus turns blue. Adding a second positive gas test cost the mark.
• Nitric acid then silver nitrate (1 mark): a cream precipitate. White or yellow was allowed only if it matched the supervisor’s results.
• The two ions in D (2 marks): ammonium and bromide. Naming bromine instead of bromide, or adding an extra ion, was rejected. If you had recorded a mixed colour such as cream-white, you had to name both halide ions to get the bromide mark.

Question 3: planning to obtain tin from cassiterite (6 marks)

Tin sits between copper and iron in the reactivity series, and cassiterite contains tin(IV) oxide, which is insoluble in water but reacts with dilute acids. You had to describe how to get tin metal from a large lump of the ore.

The mark scheme accepted four routes, each with seven marking points, and gave one mark per point up to six:

• Every route began with crushing or grinding the ore (MP1) and naming how, such as a pestle and mortar or a hammer (MP2).
• 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; in a suitable container such as a crucible; tin is displaced or reduced.
• Displacement from solution: add a dilute acid; name a strong acid (hydrochloric, sulfuric or nitric); add a more reactive metal; name it (for example iron, zinc or magnesium); tin is displaced.
• Electrolysis of the solution: dissolve in a named dilute strong acid, electrolyse with named inert electrodes (carbon or platinum), and tin forms at the cathode.
• Electrolysis of the molten oxide: heat the ore until molten, electrolyse with inert electrodes, tin forms at the cathode.

The catches: concentrated acids were rejected, a weak acid such as ethanoic acid got the “add acid” mark but not the “named acid” mark, and calcium or anything above it in the reactivity series was rejected as the displacing metal. Naming the metal does not also give you the mark for saying a more reactive metal is added, so write both. Washing, drying, weighing and crystallising steps were ignored, and a method that started from tin itself scored nothing.

Where the marks are on 0620/52

• Recording observations carried 9 of the 40 marks (2(a), 2(b), 2(c), 2(e), 2(f), 2(g)), and identifying ions carried 5 (2(d), 2(h)). The qualitative analysis notes at the back of the paper give you the expected results, so these are marks to bank.
• Data handling in Question 1 carried 14 marks: the table (4), graph (4), calculation with unit (2), reading the graph with working and unit (3) and the sketch line (1).
• “State” questions carried 4 marks (1(c)(ii), 1(e)(i), 1(e)(ii), 1(f)(i)), and the one “deduce and explain” part carried 2.
• The 6-mark plan is the single biggest written answer. It is points-based, so six short, specific steps beat a long paragraph.
• Units scored on their own twice (the rate unit in 1(c) and the volume unit in 1(d)), so leaving them off costs marks even when the number is right.

How to self-mark 0620/52 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, ora means or reverse argument and AW means alternative wording.
2. Mark the table to the scheme’s rules, not just the numbers. Did you write 10.0 for every acid volume and whole numbers for water? Does Experiment 5 show more gas than Experiment 1? Each is a separate mark.
3. Check the graph strictly. Count how many of your five points are within half a small square, confirm your scale is linear and goes above halfway, and reject your own line if it joins the dots.
4. Give the unit marks separately. In 1(c) and 1(d) the unit is its own mark, so mark the number and the unit as two decisions.
5. For observations, look for extra wrong statements. In Question 2 an otherwise correct answer loses the mark if it adds something wrong, such as fizzing with sodium hydroxide or a second gas test.
6. Mark the tin plan against one route. Pick the route closest to yours, tick each of the seven points you made and stop at six.
7. Log each lost mark as missing knowledge, a misread command word or a careless slip, and revise in that order.

Sit 0620/52 as a timed mock

The paper allows 75 minutes for 40 marks, but the experiments in Question 1 take real bench time, so give it more than its share. A workable plan:

Block	Marks	Time
Question 1: five experiments, table, graph and analysis	20	35 minutes
Question 2: tests on C and D	14	25 minutes
Question 3: tin plan	6	10 minutes
Check units, decimal places and that every observation is recorded	–	5 minutes

If you can’t do the practical at home, sit the 0620 Paper 62 version of the same experiment instead.

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 62 (Alternative to Practical)

Practise and download

• Download 0620/52 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 was on 0620 Paper 52 May/June 2026? +

Three questions: a 20-mark rate experiment timing the gas made in 75 seconds when dilute ethanoic acid reacts with sodium hydrogencarbonate at five dilutions; a 14-mark set of tests on solid C and solution D; and a 6-mark plan for getting tin metal from the ore cassiterite.

How many marks is 0620/52 and how long is it? +

It is out of 40 marks and lasts 1 hour 15 minutes. Question 1, the rate experiment, is half the paper at 20 marks.

What were the ions in solid C and solution D on 0620/52? +

Solid C contained potassium, chromium(III) and sulfate ions (lilac flame, green precipitate that dissolves in excess sodium hydroxide, white precipitate with barium nitrate). Solution D contained ammonium and bromide ions (ammonia on warming with sodium hydroxide, cream precipitate with silver nitrate).

Which experiment had the highest rate on 0620/52? +

Experiment 5, the one with the least distilled water (60 cm³) and so the most concentrated acid. The mark scheme expected the gas volume in Experiment 5 to be larger than in Experiment 1, and the rate unit cm³/s scored its own mark.

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

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 question on fractional distillation of alkanes and gives you the results to analyse instead of asking you to do the experiments.

Where can I download 0620/52 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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