AQA GCSE Chemistry Chemistry Paper 2 (Foundation), June 2023: Question 7

10 marks · Low Demand difficulty · Short Answer

Identify properties and compositions of steels, calculate the mass of titanium in an alloy, and interpret data from a table of titanium alloys.

Practise this question

Question

Question text

07 This question is about alloys.

Steels are alloys of iron.

07.1 Which non-metal element is in all steels?

[1 mark]

Tick ( ) one box.

Carbon

Iodine

Sulfur

07.2 Which two elements other than iron are in stainless steels?

[2 marks]

Tick ( ) two boxes.

Chromium

Gold

Magnesium

Nickel

Zinc 28

07.3 Give two properties of stainless steels.

Choose answers from the box.

[2 marks]

brittle hard low density

resistant to corrosion soluble in water

Property 1

*27* Property 2

Titanium is used in alloys.

Table 6 shows information about some alloys of titanium.

Table 6

Titanium alloy Other metals in alloy Strength Used in

6.0% aluminium aircraft parts

A high

4.0% vanadium hip joint replacements

5.0% aluminium

B high aircraft parts

2.5% tin

3.0% aluminium tennis rackets

C medium

2.5% vanadium heart pacemakers

07.4 Calculate the mass of titanium in 5.0 kg of titanium alloy C.

Use Table 6.

[3 marks]

29 Mass = kg

07.5 Suggest why alloy A and alloy B are used to make aircraft parts.

*28* Use Table 6.

[1 mark]

07.6 Titanium alloys used for medical purposes must not be toxic.

Suggest why alloy B is not used for medical purposes.

Use Table 6.

[1 mark]

Mark scheme

Show the mark scheme

AO /

Question Answers Extra information Mark

Spec. Ref.

07.1 carbon 1 AO1

4.10.3.2

AO /

Spec. Ref.

07.2 chromium 1 AO1

4.10.3.2

nickel 1

AO /

Spec. Ref.

07.3 in either order AO1

hard 1

4.10.3.2

resistant to corrosion 1

AO /

Spec. Ref.

07.4 (percentage of titanium = 100 – AO2

3.0 – 2.5) = 94.5 (%) 1

4.10.3.2

94.5 allow correct use of incorrectly 1

(mass =) × 5.0 determined percentage of

titanium

= 4.725 (kg) allow 4.7 / 4.73 (kg) 1

alternative approach:

5.5

(mass of Al + V = × 5.0 =)

0.275 (kg) (1)

(mass of titanium =) 5 – 0.275 allow correct use of incorrectly

(1) determin–ed mass of AHEMISTRYland V – –

= 4.725 (kg) (1) allow 4.7 / 4.73 (kg)

AO /

Question Answers Extra information Mark 19

Spec. Ref.

07.5 (both are) strong allow (both contain) more 1 AO3

aluminium

4.10.3.2

AO /

Spec. Ref.

07.6 tin is toxic allow tin reacts in the body 1 AO3

4.10.3.2

– – 8462/2F –

Total Question 7 10

Question 8

How to answer it

Alloys of Iron and Titanium

📌 What this question tests

This question tests recall and data interpretation from AQA Specification 4.10.3.2 (Alloys as useful materials):

Recall: Composition of steels (iron + carbon) and stainless steels (iron + chromium + nickel), plus properties of stainless steel.
Calculation: Calculating the mass of an element in an alloy using percentages by mass.
Analysis & Evaluation: Interpreting tabular data to justify uses of specific alloys based on physical properties and biocompatibility.

Question 07.1

Non-metal in Steels (1 mark)

✅ Correct Answer

Carbon [1 mark]

💡 Key Knowledge

All steels are alloys of iron mixed with small amounts of the non-metal carbon (typically 0.03% to 2%), often alongside other elements.

❌ Common Errors

Confusing carbon with sulfur or phosphorus. Sulfur is an unwanted impurity in blast furnace iron, not an intentionally added alloying element!

Mark allocation: 1 mark for ticking "Carbon". Any other choice loses the mark.

Question 07.2

Elements in Stainless Steels (2 marks)

✅ Correct Answer

Chromium [1 mark]
Nickel [1 mark]

💡 Key Knowledge

Stainless steel specifically contains chromium and nickel. Chromium reacts with oxygen to form an invisible, protective layer of chromium oxide that prevents rust.

🧠 Exam Technique

The prompt explicitly states "Tick (✓) two boxes". If you tick more than two, marks can be deducted for incorrect choices. Always follow instructions strictly.

Mark allocation: 1 mark per correct element. Maximum 2 marks.

Question 07.3

Properties of Stainless Steels (2 marks)

✅ Correct Answers (any order)

hard [1 mark]
resistant to corrosion [1 mark]

🧠 Exam Technique

Use the exact wording from the provided word bank. Never invent terms when given a choice box. Notice that "soluble in water" and "brittle" are completely wrong for metals.

❌ Common Errors

Selecting low density. Steels are dense materials because iron atoms have a relatively high atomic mass.

Mark allocation: 1 mark for each property. Allowed in either order.

📊 Table 6 Reference (Titanium Alloys)

Titanium alloy	Other metals in alloy	Strength	Used in
A	6.0% aluminium, 4.0% vanadium	high	aircraft parts, hip joint replacements
B	5.0% aluminium, 2.5% tin	high	aircraft parts
C	3.0% aluminium, 2.5% vanadium	medium	tennis rackets, heart pacemakers

Question 07.4

Mass of Titanium in Alloy C (3 marks)

📐 Step-by-Step Calculation

Step 1: Find percentage of titanium

% Titanium = 100% - 3.0% - 2.5% = 94.5%

[1 mark]

Step 2: Calculate mass from percentage

Mass = (94.5 / 100) × 5.0 kg

[1 mark]

Step 3: Final answer

Mass = 4.725 kg

[1 mark] (also accepts 4.7 or 4.73)

💡 Alternative Working

Step 1: Total other metals = 3.0% + 2.5% = 5.5%

Step 2: Mass of other metals = (5.5 / 100) × 5.0 = 0.275 kg

Step 3: Mass of titanium = 5.0 - 0.275 = 4.725 kg

❌ Common Errors

Calculating the mass of the other metals (0.275 kg) and forgetting to subtract from 5.0 kg.
Looking at the wrong row in Table 6 (e.g. using Alloy A or B instead of C).
Arithmetic error when subtracting percentages from 100.

Mark allocation: 1 mark for % titanium (94.5%) + 1 mark for setting up multiplication by 5.0 kg + 1 mark for correct final value (4.725 kg). Error Carried Forward (ECF) allowed.

Question 07.5

Suggest why alloy A and alloy B are used for aircraft parts (1 mark)

✅ Correct Answer

(Both are) strong / have high strength [1 mark]

Also allowed: (both contain) more aluminium

🧠 Exam Technique

The question says "Use Table 6". Look across the row for Alloy A and Alloy B under the columns. Both share "high" strength, which is vital for aircraft structural components.

❌ Common Errors

Saying "they are light" without evidence from the table. The prompt says "Use Table 6", so your justification must come directly from information given in the table.

Mark allocation: 1 mark for identifying high strength.

Question 07.6

Suggest why alloy B is NOT used for medical purposes (1 mark)

✅ Correct Answer

Tin is toxic [1 mark]

Also allowed: tin reacts in the body

💡 Key Knowledge

Comparing medical alloys (A used for hips, C used for pacemakers) to alloy B:

Alloy A: Aluminium + Vanadium
Alloy C: Aluminium + Vanadium
Alloy B: Aluminium + Tin

Since the question notes medical alloys must not be toxic, the unique metal in B (tin) must be toxic.

🧠 Exam Technique

Look for the difference! Alloy B is the only alloy containing tin, and it is the only alloy not used in medicine.

Mark allocation: 1 mark for identifying tin as toxic or reactive inside the body.

Topics

Chemistry · C10: Using Resources

Question and mark scheme from the AQA GCSE Chemistry examination, Chemistry Paper 2 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.