AQA GCSE Chemistry Chemistry Paper 1 (Foundation), June 2025: Question 1

7 marks · Low Demand difficulty · Short Answer

Identify chemical names, interpret molecular formulas, write a word equation, and balance a chemical equation for reactions involving elements and compounds.

Practise this question

Question

Question text

01 This question is about elements and compounds.

01.1 What is the name of the compound with the formula ZnBr2?

Use the periodic table.

[1 mark]

Tick ( ) one box.

Zinc bromide

Zinc chloride

Zinc iodide

01.2 A compound has the formula C2H6O

Table 1 shows information about a molecule of C2H6O

Table 1

Number of atoms of the

Symbol of element Name of element element in a molecule

of C2H6O

C 2

H Hydrogen

Oxygen 1

Complete Table 1.

Use the periodic table.

3 [3 marks]

01.3 Potassium and sulfur react to produce potassium sulfide.

Write the word equation for this reaction.

[1 mark]

*02* + ⟶

01.4 Aluminium reacts with fluorine to produce aluminium fluoride.

Balance the equation for this reaction.

[2 marks]

Al + F2 ⟶ 2 AlF3

Mark scheme

Show the mark scheme

Question 1

AO /

Question Answers Extra information Mark

Spec. Ref.

01.1 zinc bromide 1 AO2

4.1.1.1

AO /

Question Answers Mark

Spec. Ref.

01.2

Number of atoms of

Symbol of element Name of element the element in a

molecule of C2H6O

C Carbon 2 1 AO1

H Hydrogen 6 1 AO2

O Oxygen 1 1 AO1

4.1.1.1

AO /

Spec. Ref.

01.3 potassium + sulfur → potassium sulfide 1 AO2

4.1.1.1

allow 2K + S → K2S

AO /

Spec. Ref.

01.4 2Al + 3F2 → 2AlF3 allow multiples 2 AO2

4.1.1.1

allow 1 mark for 2Al

allow 1 mark for 3F2

Total Question 1 7

How to answer it

AQA GCSE Chemistry: Elements, Compounds & Equations

Topic 1: Atomic Structure & Periodic Table • Spec Ref: 4.1.1.1

What this question tests

Formula Identification: Matching chemical symbols to element names to name simple binary compounds.
Interpreting Formulae: Reading subscript numbers and chemical symbols in molecular formulae ( C₂H₆O ).
Word Equations: Constructing a word equation with correct reactant and product positioning.
Balancing Symbol Equations: Applying the law of conservation of mass to balance numbers of each atom.

Question 01.1

Naming a Compound from its Formula [1 mark]

✅ Correct Answer

Tick: Zinc bromide

💡 Key Knowledge

Zn stands for zinc.

Br stands for bromine, which changes its ending to -ide when combined into a simple compound: bromide.

🧠 Exam Technique

Always use your Periodic Table if you are unsure. Check Group 7 (halogens) to confirm the difference between chlorine ( Cl ), bromine ( Br ), and iodine ( I ).

❌ Common Errors

Confusing halide names (e.g. selecting zinc chloride or zinc iodide) through rushing and not cross-referencing with the Periodic Table.

Mark Scheme Breakdown: 1 mark for ticking 'zinc bromide'. No mark if multiple boxes are ticked without one being clearly crossed out.

Question 01.2

Interpreting Molecular Formulae [3 marks]

✅ Completed Table 1

Symbol of element	Name of element	Number of atoms of the element in a molecule of C₂H₆O
C	Carbon [1]	2
H	Hydrogen	6 [1]
O [1]	Oxygen	1

💡 Key Knowledge

Subscript numbers apply only to the element immediately before them ( H₆ means 6 hydrogen atoms).
If there is no number after an element symbol (like O in C₂H₆O ), it means there is 1 atom of that element.

❌ Common Errors

Writing lowercase o instead of capital O for oxygen. Element symbols with a single letter must always be uppercase!
Writing 0 (zero) instead of recognizing 1 oxygen atom.
Mixing up atomic numbers with the subscript count.

Mark Scheme Breakdown:
• 1 mark for Carbon
• 1 mark for 6
• 1 mark for O

Question 01.3

Writing a Word Equation [1 mark]

✅ Correct Answer

potassium + sulfur → potassium sulfide

🧠 Exam Technique

Read the question carefully: "Write the word equation". Use the exact words provided in the prompt:

Reactants before the arrow: potassium + sulfur
Product after the arrow: potassium sulfide

❌ Common Errors

Using an equals sign ( = ) instead of a reaction arrow ( → ).
Misspelling or inventing formula names (e.g. "potassium sulfate" instead of "sulfide").

💡 Examiner Insight

Although the mark scheme allows a correct balanced symbol equation ( 2 K + S → K₂S ), stick to words when a word equation is requested to avoid losing marks on incorrect chemical formulae.

Mark Scheme Breakdown: 1 mark for fully correct word equation (or correct balanced symbol equation).

Question 01.4

Balancing a Symbol Equation [2 marks]

✅ Balanced Equation

2 Al + 3 F₂ → 2 AlF₃

📐 Step-by-Step Balancing

Look at the product side first because the 2 in front of AlF₃ is already fixed:

Count atoms in product:
2 AlF₃ contains 2 Al atoms and 6 F atoms (2 × 3 = 6).
Balance Aluminium (Al):
We need 2 Al atoms on the left → write 2 before Al.
Balance Fluorine (F):
Fluorine gas is diatomic ( F₂ ). To get 6 F atoms: 6 ÷ 2 = 3 → write 3 before F₂.

❌ Common Errors

Changing the small subscript numbers (e.g. writing F₆ ). You can never change subscript numbers in an equation!
Forgetting that 2 AlF₃ multiplies the whole compound (3 fluorines × 2 = 6 fluorines total).

Mark Scheme Breakdown:
• 1 mark for 2 Al
• 1 mark for 3 F₂
• (Multiples are allowed, e.g. 4 Al + 6 F₂ → 4 AlF₃)

Topics

Chemistry · C1: Atomic Structure and the Periodic Table · C3: Quantitative Chemistry

Question and mark scheme from the AQA GCSE Chemistry examination, Chemistry Paper 1 (Foundation), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.