Inorganic chemistry of group 7: Edexcel International A Level Chemistry questions

Every Edexcel International A Level Chemistry exam question on 8C Inorganic chemistry of group 7 (specification points 8.24–8.28), 2019–2025, with its mark scheme and examiner’s report.

All 89 questions on Inorganic chemistry of group 7, as a list

June 2025, AS Unit 2, Q4 (1 mark): An aqueous solution of potassium chloride is added to a solution of iodine in hexane and shaken. After a time, two layers are formed. What is the colour of each
June 2025, AS Unit 2, Q15(a) (1 mark): When chlorine water is added to a solution of potassium bromide, a pale brown colour is seen. Write an ionic equation for this reaction. State symbols are not r
June 2025, AS Unit 2, Q15(c)(iii) (2 marks): Explain the difference in the reaction of concentrated sulfuric acid with chloride ions and with iodide ions. (2)
June 2025, AS Unit 3, Q2(b)(i) (2 marks): State the expected observations when acidified silver nitrate is added to each of these ions. (2) Chloride ion Bromide ion Iodide ion
June 2025, AS Unit 3, Q2(b)(ii) (2 marks): Explain how the identity of the halide ion can be confirmed. (2)
June 2025, AS Unit 3, Q4(b) (2 marks): State the purpose of both the anhydrous calcium chloride and the ceramic wool in the combustion tube. (2)
June 2025, AS Unit 3, Q4(d) (1 mark): State the purpose of the sodium hydroxide. (1)
June 2025, Unit 6, Q1(a)(iii) (2 marks): A white precipitate forms The formula (2) on adding a mixture of two of the anion in A is Cl–. solutions to a solution of A. The white precipitate dissolves on
January 2025, AS Unit 2, Q9 (1 mark): Concentrated sulfuric acid reacts with sodium iodide. What is one role of the sulfuric acid? A oxidising agent B reducing agent C proton acceptor D lone pair do
January 2025, AS Unit 2, Q11 (1 mark): Which is a displacement reaction that results in a visible colour change in solution? A 2NaCl + At2 → 2NaAt + Cl2 B 2NaBr + I2 → 2NaI + Br2 C 2NaI + Br2 → 2NaBr
January 2025, AS Unit 3, Q1(b)(ii) (3 marks): To another test tube of the solution, the student added silver nitrate solution. A pale yellow precipitate was observed. The student then added an excess of dil
October 2024, AS Unit 2, Q9 (1 mark): Which substance is formed when concentrated sulfuric acid reacts with solid potassium chloride? A Cl2 B S C H2S D KHSO4
October 2024, AS Unit 2, Q10 (1 mark): What is the colour of the solution formed when iodine dissolves in cyclohexane? A blue-black B grey C purple D yellow
October 2024, AS Unit 3, Q1(a)(ii) (3 marks): Describe how the presence of chloride ions in the solutions of X, Y and Z could be identified and confirmed. (3)
October 2024, Unit 6, Q1(a)(i) (4 marks): Complete the table to show, by name or formula, the products of the tests. (4) Test Observation Name or formula of product Aqueous silver nitrate and A yellow p
June 2024, AS Unit 1, Q8 (1 mark): Which is the strongest oxidising agent in these displacement reactions? Cl2 + 2Br– → Br2 + 2Cl– Br2 + 2I– → 2Br– + I2 A chlorine B bromide ions C bromine D iodi
June 2024, AS Unit 2, Q12 (1 mark): The boiling temperatures of the halogens increase down Group 7 because on descending the group the A bond polarities increase B covalent bond strengths increase
June 2024, AS Unit 2, Q14 (1 mark): Cyclohexane (density = 0.78 g cm–3) and aqueous iodine (density > 1.0 g cm–3) are shaken and left to stand. What colours are the two layers that form? lower lay
June 2024, AS Unit 3, Q2(c) (2 marks): Explain why an orange colour was seen in the round‑bottomed flask when it was first gently heated in Step 4. (2)
June 2024, AS Unit 3, Q3(c) (2 marks): The sodium hydroxide solution absorbs excess chlorine. Write the equation for the reaction between cold, dilute sodium hydroxide and chlorine. State symbols are
June 2024, Unit 6, Q5(b)(ii) (2 marks): Identify the halide X, present in NH4X, using your answer to (b)(i). (2)
June 2024, Unit 6, Q5(b)(iii) (2 marks): Give a chemical test, with the expected result, to confirm the identity of the halide ion in a sample of NH4X. (2)
June 2024 (R), AS Unit 2, Q8 (1 mark): Which statement about the elements in Group 7 is not correct? A they all exist as diatomic molecules B electronegativity decreases down the group C reactivity i
June 2024 (R), AS Unit 2, Q9 (1 mark): What are the only products formed when chlorine reacts with cold aqueous sodium hydroxide? A sodium chloride, sodium chlorate(I) and water B sodium chloride, so
June 2024 (R), AS Unit 2, Q10 (1 mark): Which statement about the reaction between concentrated sulfuric acid and potassium bromide is correct? A bromide ions are reduced B hydrogen bromide and hydrog
June 2024 (R), AS Unit 3, Q4(e) (1 mark): Under these conditions, all the silver halide precipitates can appear to be white. Identify, by name or formula, a compound, the solutions of which can be used
January 2024, AS Unit 2, Q12 (1 mark): Which row shows the correct trends down the group for the elements of Group 7? Reactivity as Boiling temperature Electronegativity oxidising agent A increases d
January 2024, AS Unit 2, Q24(b)(i) (1 mark): Give the formula of the chlorine-containing species present at highest concentration in household bleach at pH 12. (1)
January 2024, AS Unit 2, Q24(b)(ii) (3 marks): Explain why mixing strong acid with bleach is dangerous. Justify your answer using the equilibria shown. (3)
January 2024, AS Unit 2, Q24(b)(iii) (2 marks): On heating, NaClO disproportionates to form sodium chloride and sodium chlorate(V). Give the equation for this disproportionation reaction. State symbols are no
January 2024, AS Unit 3, Q3(a) (1 mark): Suggest why the iodine‑containing compounds do not burn off in Step 1. (1)
January 2024, AS Unit 3, Q3(c)(iii) (1 mark): State the colour of the aqueous iodine solution formed in Step 4. (1)
January 2024, AS Unit 3, Q3(d) (4 marks): Describe how to carry out Step 5, using a separating funnel. [Density of cyclohexane = 0.78 g cm–3] (4)
January 2024, Unit 6, Q1(b) (3 marks): Adding dilute nitric acid followed by aqueous silver nitrate to A and B resulted in both forming precipitates. The student was not certain, but suggested that t
October 2023, AS Unit 2, Q8 (1 mark): When sodium bromide reacts with concentrated sulfuric acid, sodium hydrogensulfate is always formed. What other product(s) are formed in this reaction? A hydrog
October 2023, AS Unit 2, Q19(a)(i) (1 mark): State the colour of the solid in Step 3. (1)
October 2023, AS Unit 2, Q19(c) (2 marks): Iodine may be obtained by bubbling chlorine gas through aqueous potassium iodide. When the reaction is complete, hexane is added and the mixture shaken. Two lay
October 2023, AS Unit 3, Q1(b)(i) (1 mark): Identify, by name or formula, the three anions that could be present. (1)
October 2023, AS Unit 3, Q1(b)(ii) (4 marks): Compounds A, B and C each contain a different anion. Describe the chemical tests on the precipitates formed in (b) that could be used to confirm which anion was
June 2023, AS Unit 2, Q22(d) (2 marks): Toilet cleaners that remove limescale should not be mixed with chlorine‑based disinfectants. Explain, using the relevant equation, why these two types of toilet
June 2023, AS Unit 3, Q1(a)(ii) (1 mark): Aqueous silver nitrate, acidified with dilute nitric acid, was added to a sample of solid A dissolved in distilled water. A yellow precipitate formed. Identify,
June 2023, AS Unit 3, Q1(a)(iv) (2 marks): The anion present in A can be shown by a different test on solid A. Give a suitable different test with the expected result to show the identity of this anion.
June 2023, Unit 6, Q1(a)(iii) (1 mark): A few drops of dilute (1) nitric acid were added to 5 cm3 of a fresh sample of P The formula of the A few drops of aqueous A white precipitate silver nitrate we
June 2023, Unit 6, Q1(b) (2 marks): State why, in the silver nitrate test on P, the nitric acid was not needed in this case. Justify your answer by considering the role of nitric acid in the silve
January 2023, AS Unit 2, Q11 (1 mark): Which equation shows a redox reaction that would not be expected to occur, based on the trend in reactivity of the halogens? A I2(aq) + 2At–(aq) → At2(aq) + 2I–
January 2023, AS Unit 2, Q12 (1 mark): A fixed amount of concentrated H2SO4 is reacted separately with an excess of four solid potassium halides. In which reaction would the greatest number of moles
January 2023, AS Unit 3, Q1(b) (2 marks): Q is a Group 1 halide which produces a lilac colour in a flame test. When a few drops of dilute nitric acid and aqueous silver nitrate are added to a solution o
January 2023, AS Unit 3, Q1(c)(i) (2 marks): Give an ionic equation for this reaction. Include state symbols. (2)
January 2023, AS Unit 3, Q1(c)(ii) (3 marks): A portion of the organic liquid P is added to the red‑brown aqueous solution formed in (c)(i). The mixture is shaken and then allowed to stand for several minut
January 2023, Unit 6, Q1(d)(i) (1 mark): Identify, by name or formula, two anions which might give this precipitate. (1)
January 2023, Unit 6, Q1(d)(ii) (2 marks): The precipitate formed in (d)(i) was separated from the mixture and aqueous ammonia was added. Describe how this test allows the student to distinguish between
January 2023, Unit 6, Q1(d)(iii) (2 marks): Explain why, with solution A, the precipitate must be separated before adding aqueous ammonia. (2)
October 2022, AS Unit 2, Q15 (1 mark): Which trend is not correct as Group 7 is descended? A atomic radius of the elements increases B boiling temperature of the elements increases C electronegativit
October 2022, AS Unit 2, Q21(b) (6 marks): Concentrated sulfuric acid reacts with solid potassium chloride and with solid potassium iodide. Compare and contrast these reactions to show the difference in
October 2022, AS Unit 3, Q1(b)(ii) (3 marks): State the test you would carry out on separate solutions of sodium bromide and barium chloride to show the anions present. Include the positive result for each
June 2022, AS Unit 2, Q8 (1 mark): Aqueous chlorine is added to an aqueous solution of potassium iodide. A non-polar organic solvent is then added and the mixture is shaken. The layers are allowe
June 2022, AS Unit 2, Q16(a) (2 marks): Descending the group from fluorine to iodine, the electronegativity of the atoms decreases even though their nuclear charge increases. Explain the trend in elec
June 2022, AS Unit 2, Q16(c) (1 mark): Hydrogen bromide and hydrogen iodide reduce sulfuric acid. Identify, by name or formula, the compound produced containing sulfur with its lowest oxidation numbe
June 2022, AS Unit 3, Q2(c)(ii) (3 marks): Describe a test and the expected result to confirm the presence of the chloride ion in the white solid. (3)
June 2022, Unit 6, Q1(a)(ii) (2 marks): The white precipitate is separated from the solution. Give a test on the precipitate and its positive result to confirm the identity of the anion in A. (2) Test
January 2022, AS Unit 2, Q17 (1 mark): Four tests used to identify ions are shown: 1 flame test 2 addition of acidified barium nitrate solution 3 addition of acidified silver nitrate solution 4 addit
January 2022, AS Unit 2, Q22(a) (1 mark): Use your knowledge of the trends in the properties of Group 7 elements to predict the colour and physical state of astatine at room temperature. (1)
January 2022, AS Unit 2, Q22(b)(i) (1 mark): State the meaning of the term electronegativity. (1)
January 2022, AS Unit 2, Q22(b)(ii) (2 marks): Explain the trend in electronegativity down Group 7. (2)
January 2022, AS Unit 2, Q22(c) (6 marks): Compare and contrast the reactions of chlorine with • water • cold, dilute aqueous alkali • hot, concentrated aqueous alkali Include an equation for each reacti
January 2022, AS Unit 3, Q1(a)(i) (1 mark): State what would be seen on the addition of acidified silver nitrate solution to an aqueous solution of NH4Cl. (1)
January 2022, AS Unit 3, Q3(b) (1 mark): Suggest why the red precipitate of silver chromate(VI) only forms after all the chloride ions have reacted. (1)
January 2022, AS Unit 3, Q4(a)(i) (2 marks): Explain the purpose of the anhydrous calcium chloride. (2)
January 2022, AS Unit 3, Q4(e) (1 mark): Suggest the purpose of the potassium hydroxide in the absorption tube. (1)
October 2021, AS Unit 2, Q14 (1 mark): Which statement about the Group 7 elements chlorine, bromine and iodine is not correct? A boiling temperature increases down the group B reactivity increases do
October 2021, AS Unit 2, Q15 (1 mark): When iodine is dissolved in a non-polar organic solvent, the solution formed is A purple B orange C colourless D brown
October 2021, AS Unit 2, Q17 (1 mark): Solid potassium bromide reacts with concentrated sulfuric acid. Which of these substances does not form? A bromine B hydrogen bromide C hydrogen sulfide D sulfu
June 2021, AS Unit 2, Q16 (1 mark): Which silver halides are soluble in concentrated aqueous ammonia? A AgBr and AgI B AgCl and AgI C AgCl and AgBr D AgCl only
January 2021, AS Unit 2, Q6(a) (1 mark): Which of these would not be seen? (1) A misty fumes B black solid C yellow solid D dense white smoke
January 2021, AS Unit 2, Q10 (1 mark): Which of these increases as Group 7 is descended? A oxidising ability of the molecular halogens B reducing ability of the halide ions C electrostatic attraction
January 2021, AS Unit 2, Q22(a)(i) (1 mark): Write the overall equation for the Liebig Process. State symbols are not required. (1)
January 2021, AS Unit 2, Q22(c)(i) (3 marks): Describe a chemical test on a solution of these crystals to confirm that the impurities present are chloride ions rather than bromide ions. Include the expected
January 2021, AS Unit 3, Q1(a)(iv) (3 marks): The student then mixed 1 cm3 samples of the remaining solutions as shown in Table 1. Solutions mixed Observation B and D no change B and E cream precipitate D a
October 2020, AS Unit 2, Q9 (1 mark): The products of the reaction of sodium fluoride with concentrated sulfuric acid can be predicted by considering the trends for the other sodium halides. Which g
October 2020, AS Unit 3, Q2(a) (3 marks): A student was provided with aqueous solutions of four compounds: hydrochloric acid potassium carbonate silver nitrate sodium chloride Four bottles, labelled B,
January 2020, AS Unit 2, Q6(a) (1 mark): Which statement is correct? (1) A iodide ions oxidise chlorine B iodide ions reduce chlorine C chlorine reduces iodide ions D chlorine is neither oxidised nor r
January 2020, AS Unit 2, Q6(b) (1 mark): When the reaction is complete, 10 cm3 of cyclohexane (density = 0.79 g cm−3) is added. The mixture is shaken and left to settle into two layers. Which descripti
January 2020, AS Unit 2, Q9 (1 mark): Iodine reacts with hot sodium hydroxide solution. a NaOH(aq) + b I2(aq) → c NaI(aq) + d NaIO3(aq) + e H2O(l) What are the coefficients (a, b, c, d and e) needed
January 2020, AS Unit 2, Q10(a) (1 mark): Which is correct for silver iodide? (1) Solubility in concentrated Colour of precipitate aqueous ammonia A yellow insoluble B yellow soluble C cream insoluble D
January 2020, AS Unit 2, Q16(b) (4 marks): Compare and contrast the reactions of concentrated sulfuric acid with solid potassium chloride and with solid potassium bromide. (4)
January 2020, AS Unit 3, Q1(a)(i) (2 marks): Bromine water was added to separate solutions of sodium chloride and sodium iodide. State one different observation for each reaction. (2) sodium chloride sodiu
June 2019, AS Unit 2, Q5 (1 mark): Potassium chloride reacts with concentrated sulfuric acid, producing misty fumes. It can be deduced that A sulfuric acid is acting as an oxidising agent B chlor
June 2019, AS Unit 2, Q19(b)(i) (2 marks): State the colour of each layer after separation. (2) Aqueous layer Cyclohexane layer
June 2019, AS Unit 2, Q19(c) (1 mark): The cyclohexane layer is then removed from the separating funnel and dried. Identify, by name or formula, a suitable drying agent. (1)

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