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Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Friday 13 June 2025
Morning (Time: 1 hour 20 minutes) Paper
reference WCH16/01
Chemistry
International Advanced Level
UNIT 6: Practical Skills in Chemistry II
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 50.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• There is a Periodic Table on the back cover of this paper.
Advice:
•• Read each question carefully before you start to answer it.
Try to answer every question.
• Check your answers if you have time at the end.
Turn over
P78747A
©2025 Pearson Education Ltd.
Y:1/1/1/
*P78747A0116*
, Answer ALL the questions. Write your answers in the spaces provided.
1: A student carries out tests on two inorganic salts, A and B.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(a) Salt A contains one type of cation and one type of anion.
Complete the table for the tests on a sample of the solid salt A.
Test Observations Inference
(i) Heat a small amount A is a (2)
of solid A in a test 1 . ....................................................................... hydrated salt.
tube, holding some
cobalt chloride paper at the ............................................................................
mouth of the test tube.
............................................................................
2 . .......................................................................
............................................................................
............................................................................
(ii) Add excess aqueous A pale brown precipitate The formula (1)
sodium hydroxide to a forms, which darkens of the cation
solution of A and leave to on standing. in A is
stand in air.
......................................
(iii) A white precipitate forms The formula (2)
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
on adding a mixture of two of the anion in
solutions to a solution of A. A is Cl–.
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The white precipitate
dissolves on adding an
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . excess of another solution.
Conclusion
(iv) Give the formula of salt A, which has a molar mass of 197.9 g mol–1. (2)
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...........................................................................................................................
2
*P78747A0216*
, (b) Salt B contains two types of cation and one type of anion.
Tests were carried out on separate samples of a solution of salt B.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
Test 1
Excess dilute aqueous sodium hydroxide was added and the solution warmed.
A green precipitate was observed. The precipitate turned brown on standing
in air.
A piece of damp red litmus paper was held at the mouth of the test tube. The
litmus paper turned blue.
Test 2
Acidified barium chloride solution was added.
A white precipitate was observed.
(i) Write ionic equations to account for the following observations.
State symbols are not required.
(3)
Formation of green precipitate in Test 1
Formation of gas that turned the litmus paper blue in Test 1
Formation of white precipitate in Test 2
(ii) The brown precipitate from Test 1 was dissolved in sulfuric acid.
A yellow-brown solution formed.
Give the formula of the complex ion present in the yellow-brown solution.
(1)
. . . . . . . . . . . .................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . .
(iii) State the formula of salt B.
(1)
. . . . . . . . . . . .................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . .
(Total for Question 1 = 12 marks)
3
*P78747A0316* Turn over
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Friday 13 June 2025
Morning (Time: 1 hour 20 minutes) Paper
reference WCH16/01
Chemistry
International Advanced Level
UNIT 6: Practical Skills in Chemistry II
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 50.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• There is a Periodic Table on the back cover of this paper.
Advice:
•• Read each question carefully before you start to answer it.
Try to answer every question.
• Check your answers if you have time at the end.
Turn over
P78747A
©2025 Pearson Education Ltd.
Y:1/1/1/
*P78747A0116*
, Answer ALL the questions. Write your answers in the spaces provided.
1: A student carries out tests on two inorganic salts, A and B.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(a) Salt A contains one type of cation and one type of anion.
Complete the table for the tests on a sample of the solid salt A.
Test Observations Inference
(i) Heat a small amount A is a (2)
of solid A in a test 1 . ....................................................................... hydrated salt.
tube, holding some
cobalt chloride paper at the ............................................................................
mouth of the test tube.
............................................................................
2 . .......................................................................
............................................................................
............................................................................
(ii) Add excess aqueous A pale brown precipitate The formula (1)
sodium hydroxide to a forms, which darkens of the cation
solution of A and leave to on standing. in A is
stand in air.
......................................
(iii) A white precipitate forms The formula (2)
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
on adding a mixture of two of the anion in
solutions to a solution of A. A is Cl–.
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The white precipitate
dissolves on adding an
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . excess of another solution.
Conclusion
(iv) Give the formula of salt A, which has a molar mass of 197.9 g mol–1. (2)
.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...........................................................................................................................
2
*P78747A0216*
, (b) Salt B contains two types of cation and one type of anion.
Tests were carried out on separate samples of a solution of salt B.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
Test 1
Excess dilute aqueous sodium hydroxide was added and the solution warmed.
A green precipitate was observed. The precipitate turned brown on standing
in air.
A piece of damp red litmus paper was held at the mouth of the test tube. The
litmus paper turned blue.
Test 2
Acidified barium chloride solution was added.
A white precipitate was observed.
(i) Write ionic equations to account for the following observations.
State symbols are not required.
(3)
Formation of green precipitate in Test 1
Formation of gas that turned the litmus paper blue in Test 1
Formation of white precipitate in Test 2
(ii) The brown precipitate from Test 1 was dissolved in sulfuric acid.
A yellow-brown solution formed.
Give the formula of the complex ion present in the yellow-brown solution.
(1)
. . . . . . . . . . . .................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . .
(iii) State the formula of salt B.
(1)
. . . . . . . . . . . .................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . .
(Total for Question 1 = 12 marks)
3
*P78747A0316* Turn over
