Cambridge O Level · 5070 · Paper 2 · Theory

Chemistry 5070/21 May/June 2025 past paper

Cambridge O Level Chemistry (5070) Paper 2 (Theory), variant 1, May/June 2025: the question paper and its official mark scheme, 8 questions worth 80 marks, with the grade thresholds. Free to open, no account needed.

Questions: 8
Marks: 80
Grade A from: 54

Open the question paper Mark scheme

File names: 5070_s25_qp_21 · 5070_s25_ms_21

Grade thresholds for 5070/21 May/June 2025

The minimum raw marks Cambridge set for each grade on this component (out of 80). Thresholds change every session and variant, so always compare your score with the paper you actually sat.

A	B	C	D	E
54	39	23	18	13

Topics in this paper

Which syllabus chapters 5070/21 May/June 2025 tested, by marks. Each chapter links to every past-paper question on it.

Chapter	Questions	Marks
Organic chemistry	2	23
Acids, bases and salts	2	22
Electrochemistry	2	14
Chemistry of the environment	1	12
Atoms, elements and compounds	1	9

Questions in 5070/21 May/June 2025

Question 1Electrochemistry · 5 marks
Choose from the following salts to answer the questions. aluminium chloride barium sulfate calcium chloride copper(II) sulfate magnesium chloride potassium iodide potassium manganate(VII) silver nitrate sodium bromide sodium sulfite Each salt can be used once, more than once or not …
Question 2Electrochemistry · 9 marks
A concentrated aqueous solution of copper(II) bromide is electrolysed using graphite electrodes. (a) Graphite has good electrical conductivity. (i) Explain why graphite has good electrical conductivity. Use ideas about structure and bonding. (ii) State one other property of graphite that …
Question 3Atoms, elements and compounds · 9 marks
The equation for the reaction between methane and chlorine is shown in Fig. …
Question 4Organic chemistry · 12 marks
Ethanol, C2H5OH, is a member of the homologous series of alcohols. (a) Give the general formula of the homologous series of alcohols. (b) Members of a homologous series have the same general formula and share similar chemical properties. State two …
Question 5Chemistry of the environment · 12 marks
Vehicles that use petrol as a fuel produce several air pollutants. (a) Petrol is a mixture of hydrocarbons which includes octane, C8H18. Explain why octane is a hydrocarbon. (b) Two of the air pollutants produced are carbon monoxide and nitrogen …
Question 6Acids, bases and salts · 16 marks
Chlorine, Cl 2, is in Group VII of the Periodic Table. (a) The melting point of chlorine is –101 °C and the boiling point is …
Question 7Acids, bases and salts · 6 marks
Aluminium is used in the manufacture of aircraft and food containers. Aluminium is resistant to corrosion by water and oxygen. (a) Give one other reason why aluminium is used in the manufacture of aircraft. (b) Explain why aluminium is resistant …
Question 8Organic chemistry · 11 marks
Fig. 8.1 shows the displayed formula of methylbut‑2‑enoate. …

Other Chemistry papers from May/June 2025

Questions students ask

Where can I get the 5070/21 May/June 2025 mark scheme?

Open the mark scheme above - it is the official Cambridge scheme for this exact paper (5070_s25_ms_21), and on a wide screen it sits beside the question you are reading.

What was the grade threshold for an A in 5070/21 May/June 2025?

54 marks out of 80, a C needed 23.

Which topics came up in 5070/21 May/June 2025?

Mostly Organic chemistry, Acids, bases and salts, Electrochemistry. The full list is in the table above.

Do I need an account to open 5070/21 May/June 2025?

No. Every paper opens for free without signing in. A free account also saves your pen marks and records your score against the grade thresholds.