Pearson Edexcel International Advanced Level Chemistry UNIT 1 MAY 2025 QUESTION PAPER: Structure, Bonding and Introduction to Organic Chemistry

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Pearson Edexcel International Advanced Level
Wednesday 07 May 2025
Morning (Time: 1 hour 30 minutes) Paper
reference WCH11/01
Chemistry  


International Advanced Subsidiary/Advanced Level
UNIT 1: Structure, Bonding and Introduction to
Organic Chemistry

You must have: Total Marks
Scientific calculator, ruler



Instructions:
•• Use black ink or ball‑point pen.
If pencil is used for diagrams/sketches/graphs it must be dark (HB or B).
• Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.

Information:
•• The total mark for this paper is 80.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• You will be assessed on your ability to organise and present information, ideas,
descriptions and arguments clearly and logically, including your use of grammar,
punctuation and spelling.
• A Periodic Table is printed on the back cover of this paper.

Advice:
• Read each question carefully before you start to answer it.
• Show all your working in calculations and include units where appropriate.
•• Checkanswer
Try to every question.
your answers if you have time at the end.
Turn over


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©2025 Pearson Education Ltd.
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*P78742A0124*

, SECTION A
Answer ALL the questions in this section.




DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
You should aim to spend no more than 20 minutes on this section.
For each question, select one answer from A to D and put a cross in the box . If you change
your mind, put a line through the box and then mark your new answer with a cross .
1: Which row shows the numbers of neutrons and electrons in a bromide ion 79Br– ?

Number of Number of
neutrons electrons
A 44 35
B 44 36
C 46 35
D 46 36


(Total for Question 1 = 1 mark)

2: What volume of sulfur dioxide gas reacts completely with 50 cm3 of 0.12 mol dm–3
sodium hydroxide solution?
[molar volume of a gas = 24 dm3 at room temperature and pressure]

SO2 + 2NaOH → Na2SO3 + H2O


A 0.072 dm3

B 0.144 dm3

C 0.288 dm3

D 72 dm3
(Total for Question 2 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.




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, 3: Which amount does not have a mass of approximately 6 g?

A 0.33 mol water (H2O; Mr = 18)
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA




B 0.25 mol magnesium (Mg; Ar = 24.3)

C 0.033 mol glucose (C6H12O6 ; Mr = 180)

D 0.025 mol copper(II) sulfate (CuSO4 ; Mr = 159.6)
(Total for Question 3 = 1 mark)

4: How many molecules of H2O are present in 1 drop (0.050 cm3) of water?
[L = 6.02 × 1023, density of water = 1 g cm–3]

A 2.17 × 1026

B 6.69 × 1023

C 1.67 × 1022
D 1.67 × 1021
(Total for Question 4 = 1 mark)

5: Which mass of fertiliser contains 467 g of nitrogen?

A 2 kg sodium nitrate (NaNO3 ; Mr = 85)

B 1 kg urea (NH2CONH2 ; Mr = 60)

C 1 kg ammonium nitrate (NH4NO3 ; Mr = 80)

D 1 kg ammonium sulfate ((NH4)2SO4 ; Mr = 132.1)
(Total for Question 5 = 1 mark)

6: Which is the correct order for the processes in a mass spectrometer?


A deflection detection ionisation vaporisation

B vaporisation ionisation deflection detection

C ionisation vaporisation deflection detection

D vaporisation deflection ionisation detection

(Total for Question 6 = 1 mark)




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