Elements, compounds and mixtures: Edexcel International GCSE Chemistry questions

Every Edexcel International GCSE Chemistry exam question on Elements, compounds and mixtures (specification points 1.8–1.13), 2019–2025, with its mark scheme and examiner’s report.

All 145 questions on Elements, compounds and mixtures, as a list

June 2025, Paper 1, Q3(a) (2 marks): Explain why the start line on the paper is drawn in pencil rather than in ink. (2)
June 2025, Paper 1, Q3(b) (2 marks): Explain which two inks contain the dye that is most soluble in the solvent. (2)
June 2025, Paper 1, Q3(c) (3 marks): Explain how the chromatogram shows that • W contains only one dye • V may contain more than one dye (3)
June 2025, Paper 1, Q3(d) (4 marks): Calculate the Rf value for the dye in W. Give your answer to two significant figures. (4) Rf value =
June 2025, Paper 1, Q4(a)(i) (1 mark): What is the total number of atoms in the formula Ca3(PO4)2? (1) A 8 B 11 C 13 D 19
June 2025, Paper 2, Q1(a)(i) (1 mark): Give the name of a compound. (1)
June 2025, Paper 2, Q1(a)(ii) (1 mark): Give the name of a mixture. (1)
June 2025, Paper 2, Q1(a)(iv) (1 mark): Give the name of a metal element. (1)
June 2025 (R), Paper 1, Q3(c)(i) (1 mark): Give the number of different elements in copper(II) hydroxide. (1)
November 2024, Paper 1, Q2(b) (2 marks): Explain why hydrogen chloride is classified as a compound. (2)
November 2024, Paper 1, Q4(a) (5 marks): Describe how the student should set up the apparatus and do the experiment. You may use a diagram to help your answer. (5)
November 2024, Paper 1, Q4(b)(i) (2 marks): Explain which ink contains a dye that is insoluble in the solvent. (2)
November 2024, Paper 1, Q4(b)(ii) (2 marks): Explain which inks contain the same dye. (2)
November 2024, Paper 1, Q4(b)(iii) (2 marks): Describe how the student can use the chromatogram to determine the Rf value for the dye in ink C. You do not need to calculate the Rf value. (2)
November 2024, Paper 1, Q7(a)(i) (1 mark): Give a reason why the student surrounds tube B with ice. (1)
November 2024, Paper 2, Q3(a) (1 mark): Give the name of this method of separation. (1) A chromatography B crystallisation C filtration D fractional distillation
November 2024, Paper 2, Q3(b) (3 marks): Name the pieces of apparatus labelled X, Y and Z. (3) X Y Z
November 2024, Paper 2, Q3(c) (2 marks): Give a physical test that the teacher could do to find out if the ethanol produced is pure. (2)
June 2024, Paper 1, Q4(a)(i) (1 mark): Determine the number of atoms in one molecule of caffeine. (1)
June 2024, Paper 1, Q4(b)(i) (1 mark): Give the name of the method of separation shown in the diagram. (1)
June 2024, Paper 1, Q4(b)(ii) (2 marks): Describe what happens to the ethanol vapour in apparatus X. (2)
June 2024, Paper 1, Q5(a)(i) (2 marks): The chromatography paper is placed in a solvent. Explain why the spots on the baseline are placed above the level of the solvent. (2)
June 2024, Paper 1, Q5(a)(ii) (2 marks): Explain which two felt tip pens contain the same dye. (2)
June 2024, Paper 1, Q5(a)(iii) (2 marks): The student thought that both F and G contained only one dye. Explain why the student can only be certain about one of these dyes. (2)
June 2024, Paper 1, Q5(b) (3 marks): Calculate the Rf value for the dye in G. Show your working. (3) Rf value =
June 2024 (R), Paper 1, Q3(a)(i) (1 mark): Identify a method to remove sand from a mixture of sand and seawater. (1)
June 2024 (R), Paper 1, Q3(a)(ii) (1 mark): Identify a method to separate a mixture of liquids with different boiling points. (1)
June 2024 (R), Paper 1, Q3(b) (2 marks): The diagram shows part of the structure of silicon dioxide. oxygen silicon Explain why silicon dioxide is a compound. (2)
June 2024 (R), Paper 1, Q3(c)(i) (1 mark): Determine the number of different elements in C257H383N65O77S6 (1)
June 2024 (R), Paper 1, Q3(c)(ii) (1 mark): Determine the number of atoms in a molecule of C257H383N65O77S6 (1) number of atoms =
June 2024 (R), Paper 1, Q3(d) (2 marks): Magnalium is a mixture of magnesium atoms and aluminium atoms. The diagram shows a sample of magnalium. magnesium atom aluminium atom Calculate the percentage o
June 2024 (R), Paper 1, Q5(a)(i) (3 marks): Complete the diagram by adding the missing labels. (3)
June 2024 (R), Paper 1, Q5(a)(ii) (1 mark): Give a reason why the baseline is drawn in pencil. (1)
June 2024 (R), Paper 1, Q5(b)(i) (1 mark): Which two food colourings contain the same dye? (1) A W and X B W and Y C X and Z D Y and Z
June 2024 (R), Paper 1, Q5(b)(ii) (2 marks): Calculate the Rf value of the dye in food colouring W. (2) Rf =
June 2024 (R), Paper 1, Q11(a) (1 mark): Give a reason why diamond is an element. (1)
November 2023, Paper 1, Q4(a)(vii) (1 mark): Give a reason why it is not possible to give information for air in the table. (1)
June 2023, Paper 1, Q1(a)(i) (1 mark): Give the best method for obtaining gasoline from crude oil. (1)
June 2023, Paper 1, Q1(a)(ii) (1 mark): Give the best method for separating the dyes in black ink. (1)
June 2023, Paper 1, Q1(a)(iii) (1 mark): Give the best method for obtaining pure water from seawater. (1)
June 2023, Paper 1, Q1(b) (4 marks): A sample of solid hydrated copper(II) sulfate can be obtained from a mixture of copper(II) oxide and copper(II) sulfate. Complete the passage by using words fro
June 2023, Paper 1, Q9(a)(i) (1 mark): How many different elements are there in the formula Na2SO4.7H2O? (1) A 3 B 4 C 5 D 10
June 2023, Paper 1, Q9(a)(ii) (1 mark): What is the total number of atoms in the formula Na2SO4.7H2O? (1) A 10 B 22 C 27 D 28
June 2023, Paper 1, Q9(b)(ii) (2 marks): Explain the role of the ice in the beaker. (2)
June 2023, Paper 1, Q9(b)(iii) (2 marks): Describe how the student could prove that the liquid collected is pure water. (2)
June 2023 (R), Paper 1, Q2(a) (3 marks): The box gives some techniques used to separate mixtures. crystallisation filtration fractional distillation simple distillation The table lists some substances
June 2023 (R), Paper 1, Q2(b) (1 mark): State how the box represents a mixture. (1)
June 2023 (R), Paper 1, Q2(c) (2 marks): Food colourings are mixtures of food dyes. A student uses paper chromatography to separate the food dyes contained in food colouring D. The student places spots
June 2023 (R), Paper 1, Q2(d)(i) (1 mark): Determine the number of different elements in Ca(HCO3)2 (1)
June 2023 (R), Paper 1, Q2(d)(ii) (1 mark): Determine the number of atoms in the formula of Ca(HCO3)2 (1)
June 2023 (R), Paper 1, Q7(b)(iii) (2 marks): Give a physical test to show that the water that collects in the U-tube is pure. (2)
January 2023, Paper 1, Q2(a) (1 mark): Which of these is the formula of a molecule of an element? (1) A O B Cl2 C HCl D H2O
January 2023, Paper 1, Q2(b) (1 mark): Which method can be used to separate an insoluble solid from a liquid? (1) A crystallisation B evaporation C filtration D simple distillation
January 2023, Paper 1, Q2(c) (1 mark): Give the name of a method used to separate a mixture of liquids with different boiling points. (1)
January 2023, Paper 1, Q4(a) (4 marks): Explain two mistakes that the student makes when setting up the apparatus. (4) 1 2
January 2023, Paper 1, Q4(b)(i) (2 marks): Complete the chromatogram for food colouring A by adding and labelling the dyes. (2) A
January 2023, Paper 1, Q4(b)(ii) (1 mark): Give a reason why the blue dye has a larger R f value than the yellow dye. (1)
January 2023, Paper 1, Q12(b) (2 marks): Describe a physical test to show that the water in tube B is pure. (2) QUESTION 12 CONTINUES ON NEXT PAGE
June 2022, Paper 1, Q2(b)(ii) (1 mark): State what the student should do next to separate the sand from the salt solution. (1)
June 2022, Paper 1, Q2(b)(iii) (4 marks): Describe how the student can obtain pure dry crystals of salt from the salt solution. (4)
June 2022, Paper 1, Q9(a)(iv) (2 marks): Describe a physical test to show that the water produced in this reaction is pure. (2)
June 2022 (R), Paper 1, Q2(b)(i) (2 marks): Explain why it is necessary for water to flow continuously in and out of the apparatus. (2)
June 2022 (R), Paper 1, Q2(b)(iii) (2 marks): Describe a physical test to show that the liquid in the conical flask is pure water. (2)
June 2022 (R), Paper 1, Q3(a)(i) (1 mark): Give the letter of the food colouring that contains three different food dyes. (1)
June 2022 (R), Paper 1, Q3(a)(ii) (1 mark): Give the letters of the two food colourings that contain the same dye. (1)
June 2022 (R), Paper 1, Q3(a)(iii) (2 marks): Using the scale on the diagram, determine the Rf value of the dye in food colouring C. (2) Rf =
June 2022 (R), Paper 1, Q3(a)(iv) (1 mark): Give a reason why the dye in food colouring D moves the furthest from the start line. (1)
June 2022 (R), Paper 1, Q3(b) (4 marks): Describe how a student could obtain a chromatogram similar to the one shown in the diagram. (4)
June 2022 (R), Paper 1, Q10(b)(ii) (1 mark): Name a technique the student could use to separate barium sulfate from the mixture after 100 cm3 of dilute sulfuric acid has been added. (1)
January 2022, Paper 1, Q1(a)(i) (1 mark): Identify a method to separate a single food dye from a mixture of food dyes. (1)
January 2022, Paper 1, Q1(a)(ii) (1 mark): Identify a method to separate gasoline from crude oil. (1)
January 2022, Paper 1, Q1(a)(iii) (1 mark): Identify a method to separate water from copper(II) sulfate solution. (1)
January 2022, Paper 1, Q1(b) (2 marks): The diagram represents a molecule. Explain why this molecule is a compound. (2)
January 2022, Paper 1, Q1(c)(i) (1 mark): State the number of different elements in C3H5N3O9 (1)
January 2022, Paper 1, Q1(c)(ii) (1 mark): Determine the number of atoms in a molecule of C3H5N3O9 (1)
January 2022, Paper 1, Q11(a)(ii) (2 marks): Describe a physical test to show the colourless liquid is pure water. (2)
January 2022 (R), Paper 1, Q2(a)(i) (1 mark): State the meaning of the term solute. (1)
January 2022 (R), Paper 1, Q2(a)(ii) (1 mark): State the meaning of the term solvent. (1)
January 2022 (R), Paper 1, Q2(b) (2 marks): Explain what is meant by a saturated solution. (2)
January 2022 (R), Paper 1, Q3(a) (2 marks): State two things that should be the same in both experiments so that the students can compare their results fairly. (2) 1 2
January 2022 (R), Paper 1, Q3(b)(i) (1 mark): State what can be concluded about dye C. (1)
January 2022 (R), Paper 1, Q3(b)(ii) (2 marks): Explain which Rf value cannot be correct. (2)
January 2022 (R), Paper 1, Q3(c) (3 marks): The diagram shows a chromatogram for a different food dye. Some distances are shown on the diagram. top of paper 2.0 cm solvent front 2.3 cm 9.7 cm start line b
January 2022 (R), Paper 2, Q1(b)(i) (1 mark): Give the name of a non-metallic element. (1)
January 2022 (R), Paper 2, Q1(b)(ii) (1 mark): Give the name of a compound. (1)
November 2021, Paper 1, Q1(a)(i) (1 mark): Which substance contains single atoms of one element? (1) A B C D
November 2021, Paper 1, Q1(a)(ii) (1 mark): Which substance is a compound? (1) A B C D
November 2021, Paper 1, Q1(a)(iii) (1 mark): Which substance could have the formula H2? (1) A B C D
November 2021, Paper 1, Q1(b) (2 marks): The diagram shows the particles in substance E. E Give two reasons why substance E is a mixture. (2) 1 2
November 2021, Paper 1, Q10(a)(i) (1 mark): Name this method of separation. (1)
November 2021, Paper 1, Q10(c)(ii) (2 marks): Describe a physical test to show if the colourless liquid is pure water. (2)
June 2021, Paper 1, Q3(b)(i) (1 mark): Name the process used to obtain pure water from the sugar solution. (1)
June 2021, Paper 1, Q3(b)(ii) (2 marks): Explain the purpose of the piece of apparatus labelled X. (2)
June 2021, Paper 1, Q4(a)(i) (3 marks): Describe how the student should complete the experiment after putting a spot of each food colouring on the paper. (3)
June 2021, Paper 1, Q4(a)(ii) (1 mark): Deduce the number of dyes in food colouring H. (1)
June 2021, Paper 1, Q4(a)(iii) (1 mark): Suggest why food colouring F does not move during the experiment. (1)
June 2021, Paper 1, Q4(a)(iv) (2 marks): Explain which two food colourings contain the dye that is likely to be the most soluble in the solvent. (2)
June 2021, Paper 1, Q4(b) (3 marks): Determine which food colouring contains a dye with Rf value closest to 0.67 Show your working. (3)
January 2021, Paper 1, Q2(c) (1 mark): Suggest how the melting point of a pure substance changes when an impurity is added. (1)
January 2021, Paper 1, Q3(c)(i) (1 mark): Give the number of different elements in lead nitrate. (1)
January 2021, Paper 1, Q5(a) (4 marks): The box gives some methods used to separate mixtures. crystallisation filtration fractional distillation simple distillation Complete the table by giving the co
January 2021, Paper 1, Q5(b)(i) (2 marks): Explain which dyes are contained in the purple ink. (2)
January 2021, Paper 1, Q5(b)(ii) (2 marks): Explain which dye is least soluble in the solvent. (2)
January 2021, Paper 1, Q5(c) (2 marks): A different chromatography experiment is set up. A spot of food colouring is placed on the start line. A food dye in the colouring has an Rf value of 0.72 The d
January 2021 (R), Paper 1, Q1(b) (1 mark): Name a compound. (1)
January 2021 (R), Paper 1, Q1(c) (1 mark): Name a mixture. (1)
January 2021 (R), Paper 1, Q1(d) (1 mark): Name an element that is a gas at room temperature. (1)
January 2021 (R), Paper 1, Q2(a) (2 marks): Deduce what conclusions can be made about the composition of ink 1. (2)
January 2021 (R), Paper 1, Q2(b)(i) (1 mark): Give one conclusion that can be made about ink 2. (1)
January 2021 (R), Paper 1, Q2(b)(ii) (1 mark): Suggest how the student could change the experiment to find the composition of ink 2. (1)
January 2021 (R), Paper 1, Q2(c) (3 marks): Calculate the Rf value of dye C, giving your answer to 2 significant figures. (3) Rf value =
November 2020, Paper 1, Q2(b) (3 marks): A student has two solids, X and Y. One of these solids is a pure substance and the other is a mixture. Describe how the student could identify which solid is pu
November 2020, Paper 2, Q1(a) (1 mark): She separates the sand from the salt solution. Which method of separation should she use? (1) A crystallisation B filtration C fractional distillation D simple
November 2020, Paper 2, Q1(b)(i) (3 marks): Name the pieces of apparatus labelled X, Y and Z. (3) X Y Z
November 2020, Paper 2, Q1(b)(ii) (1 mark): State what remains in the flask when the separation is complete. (1)
November 2020, Paper 2, Q2(a) (1 mark): Which of the unknown substances contains only one food dye? (1) A substance S B substance T C substance U D substance V
November 2020, Paper 2, Q2(b) (2 marks): Explain which pure food dyes are in substance V. (2)
November 2020, Paper 2, Q2(c)(i) (3 marks): Calculate the Rf value of the yellow food dye Y. (3) Rf =
November 2020, Paper 2, Q2(c)(ii) (1 mark): State how the chromatogram suggests that the yellow food dye Y is less soluble in the solvent than the red food dye R. (1)
November 2020 (R), Paper 1, Q1(a)(i) (1 mark): Identify the method used to obtain pure water from sea water. (1)
November 2020 (R), Paper 1, Q1(a)(ii) (1 mark): Identify the method used to separate the dyes in a food colouring. (1)
November 2020 (R), Paper 1, Q1(a)(iii) (1 mark): Identify the method used to obtain ethanol from a mixture of ethanol and water. (1)
November 2020 (R), Paper 1, Q1(b) (3 marks): Complete the sentences by writing a suitable word in each blank space. (3) When salt is added to water and stirred until no more will , a saturated solution for
November 2020 (R), Paper 2, Q1(a) (4 marks): Complete the table by giving the name of each piece of apparatus. (4) Letter Name A B C D
November 2020 (R), Paper 2, Q1(b) (1 mark): Which piece of apparatus can be used to measure the volume of a liquid? (1) A B C D
January 2020, Paper 2, Q1(b) (1 mark): Name the technique used to separate the mixture of colours in black ink. (1)
January 2020, Paper 2, Q1(c)(i) (1 mark): Identify the compound. (1)
January 2020, Paper 2, Q1(c)(ii) (1 mark): Identify the mixture. (1)
January 2020 (R), Paper 2, Q1(a)(i) (1 mark): Which box represents a mixture? (1) A 1 B 2 C 3 D 4
January 2020 (R), Paper 2, Q1(a)(ii) (1 mark): Which two boxes represent elements? (1) A 1 and 2 B 2 and 3 C 1 and 3 D 3 and 4
January 2020 (R), Paper 2, Q1(a)(iii) (2 marks): Explain why Box 5 represents a compound. (2)
January 2020 (R), Paper 2, Q2(a) (2 marks): The diagram shows that the student makes two mistakes when setting up her apparatus. State the two changes that the student should make so that her experiment w
January 2020 (R), Paper 2, Q2(b)(i) (3 marks): Explain what the chromatogram shows about the composition of the green food colouring. (3)
January 2020 (R), Paper 2, Q2(b)(ii) (3 marks): The distance between the start line and the spot for dye C is 6.2 cm. Calculate the Rf value of dye C. (3) Rf value =
January 2020 (R), Paper 2, Q2(b)(iii) (1 mark): Suggest why dye A does not move. (1)
June 2019, Paper 1, Q4(a) (4 marks): Explain two mistakes the student made when setting up his experiment. (4) 1 2
June 2019, Paper 1, Q4(b)(i) (1 mark): State how many colours ink D contains. (1)
June 2019, Paper 1, Q4(b)(ii) (1 mark): State which of the inks tested could be mixed together to make ink D. (1)
June 2019, Paper 1, Q4(b)(iii) (2 marks): Explain which of the inks tested is insoluble in water. (2)
June 2019 (R), Paper 1, Q3(a) (4 marks): Describe how the student should set up and carry out her experiment. You may draw a diagram to help with your answer. (4)
June 2019 (R), Paper 1, Q3(b) (2 marks): Explain why the line on the paper is drawn in pencil rather than in ink. (2)
June 2019 (R), Paper 1, Q3(c)(i) (2 marks): Explain which ink contains a dye that is insoluble in the solvent. (2)
June 2019 (R), Paper 1, Q3(c)(ii) (2 marks): Explain which two inks contain the dye that is likely to be the most soluble in the solvent. (2)
June 2019 (R), Paper 1, Q3(c)(iii) (2 marks): Explain which two inks may contain only one dye. (2)
June 2019 (R), Paper 1, Q3(d) (3 marks): One dye in ink Y moves 4.3 cm when the solvent front moves 6.5 cm. Calculate the Rf value for this dye. Give your answer to 2 significant figures. (3) Rf value

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