Chemistry Worked Exam Solutions. Mark Scheme ATTACHED.
Tuesday 13 May 2025 [VERIFIED]
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AS
CHEMISTRY
Paper 1 Inorganic and Physical Chemistry
Tuesday 13 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have:
For Examiner’s Use
the Periodic Table/Data Sheet, provided as an insert (enclosed)
a ruler with millimetre measurements Question Mark
a scientific calculator, which you are expected to use where appropriate.
1
Instructions 2
Use black ink or black ball-point pen. 3
Fill in the boxes at the top of this page. 4
Answer all questions.
5
You must answer the questions in the spaces provided. Do not write outside the box around each page
or on blank pages. 6
If you need extra space for your answer(s), use the lined pages at the end of this book. Write the 7
question number against your answer(s). Section B
All working must be shown.
Do all rough work in this book. Cross through any work you do not want to be marked. TOTAL
Information
The marks for questions are shown in brackets.
The maximum mark for this paper is 80.
Advice
You are advised to spend 65 minutes on Section A and 25 minutes on Section B.
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Section A box
Answer all questions in this section.
0 1 This question is about the extraction of titanium.
The first stage in the extraction of titanium is the formation of titanium(IV) chloride, TiCl4
TiO2(s) + 2 C(s) + 2 Cl2(g) ⟶ TiCl4(l) + 2 CO(g)
0 1 . 1 Calculate the percentage atom economy to form TiCl4 in this first stage of the extraction.
[2 marks]
Percentage atom economy
0 1 .2 Suggest one economic advantage of using a process with a high percentage
atom economy.
[1 mark]
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The second stage of the extraction is the reaction between TiCl4 and magnesium. box
0 1 . 3 Give the equation for the reaction between TiCl4 and magnesium. State the role of
magnesium in this reaction.
[2 marks]
Equation
Role of magnesium
0 1 4 . Titanium is an expensive metal because its extraction process uses magnesium.
Suggest why magnesium is expensive.
[1 mark]
6
Turn over for the next question
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There are no questions printed on this page box
DO NOT WRITE ON THIS PAGE
ANSWER IN THE SPACES PROVIDED
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0 2 This question is about the halogens and their compounds.
0 2 . 1 Table 1 shows the boiling points of some halogens.
Table 1
Halogen Boiling point / °C
Fluorine –188
Chlorine –35
Bromine 59
Explain the trend in the boiling points of these halogens.
[2 marks]
0 2 . 2 Chlorine is toxic but is added to drinking water.
State why chlorine is added to drinking water.
Explain why this is safe to do even though chlorine is toxic.
[2 marks]
Why chlorine is added
Why this is safe
Question 2 continues on the next page
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