The chemical properties of the halogen elements and the hydrogen halides — Paper 1 · A Level Chemistry 9701

17 What happens when chlorine is bubbled through aqueous potassium iodide? A Chlorine is oxidised to chloride ions. B Hydrochloric acid is formed. C Iodide ions are oxidised to iodine. D Potassium iodide is reduced to iodine.

1 marks

Answer: C

This question in 9701/11 May/June 2006

15 Which of the following is not a correct statement about iodine? A A crystal of iodine contains covalent bonds and van der Waals’ forces. B Iodine vapour is purple. C The first ionisation energy of iodine is less than that of bromine. D The hydride of iodine is of greater thermal stability than that of bromine.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2006

17 Which is the complete list of all the products from the reaction of concentrated sulphuric acid with potassium bromide? A potassium hydrogensulphate and hydrogen bromide B potassium hydrogensulphate, hydrogen bromide and bromine C potassium hydrogensulphate, hydrogen bromide, bromine and water D potassium hydrogensulphate, hydrogen bromide, bromine, water and sulphur dioxide

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2006

23 Limonene is an oil formed in the peel of citrus fruits. CH3 CH2 C CH3 limonene Which product is formed when molecular bromine reacts with limonene at room temperature in the dark? A B C D Br Br CH3 CH2 CH3 CH2 C C CH3 C CH2Br CH3 C CH2Br Br Br Br CH3 CH3 Br CH3 CH3 Br

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2007

16 Properties of chlorine, iodine and their compounds are compared. Property Q for chlorine is smaller than for iodine. What is property Q? A oxidising ability of the element B solubility of the silver halide in NH3(aq) C strength of van der Waals’ forces between the molecules of the element D thermal stability of the hydrogen halide

1 marks

Answer: C

This question in 9701/11 May/June 2008

16 Which statement is most likely to be true for astatine, which is below iodine in Group VII of the Periodic Table? A Astatine and aqueous potassium chloride react to form aqueous potassium astatide and chlorine. B Potassium astatide and hot dilute sulfuric acid react to form white fumes of only hydrogen astatide. C Silver astatide reacts with dilute aqueous ammonia in excess to form a solution of a soluble complex. D Sodium astatide and hot concentrated sulfuric acid react to form astatine.

1 marks

Answer: D

This question in 9701/11 May/June 2009

36 Which properties in the sequence hydrogen chloride, hydrogen bromide and hydrogen iodide steadily increase? 1 thermal stability 2 bond length 3 ease of oxidation

1 marks

Answer: C

This question in 9701/11 May/June 2009

13 How does concentrated sulfuric acid behave when it reacts with sodium chloride? A as an acid only B as an acid and oxidising agent C as an oxidising agent only D as a reducing agent only

1 marks

Answer: A

This question in 9701/11 May/June 2010

14 How does concentrated sulfuric acid behave when it reacts with sodium chloride? A as an acid only B as an acid and oxidising agent C as an oxidising agent only D as a reducing agent only

1 marks

Answer: A

This question in 9701/12 May/June 2010

33 Which reactions are redox reactions? 1 CaBr2 + 2H2SO4 → CaSO4 + Br2 + SO2 + 2H2O 2 CaBr2 + 2H3PO4 → Ca(H2PO4)2 + 2HBr 3 CaBr2 + 2AgNO3 → Ca(NO3)2 + 2AgBr

1 marks

Answer: D

This question in 9701/12 May/June 2010

11 How does concentrated sulfuric acid behave when it reacts with sodium chloride? A as an acid only B as an acid and oxidising agent C as an oxidising agent only D as a reducing agent only

1 marks

Answer: A

This question in 9701/13 May/June 2010

16 What happens when chlorine is bubbled through aqueous potassium iodide? A Chlorine is oxidised to chlorate(V) ions. B Chlorine is oxidised to chloride ions. C Iodide ions are oxidised to iodine. D There is no observable reaction.

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2010

19 Concentrated sulfuric acid reacts with both solid sodium chloride at room temperature and with solid sodium iodide at room temperature. Which row correctly describes how concentrated sulfuric acid behaves in each of these reactions? with sodium chloride with sodium iodide A as an oxidising agent only as an oxidising agent only B as a strong acid and as an oxidising agent as a strong acid only C as a strong acid only as a strong acid and as an oxidising agent D as a strong acid only as a strong acid only

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2010

15 X, Y and Z represent different halogens. The table shows the results of nine experiments in which aqueous solutions of X2, Y2 and Z2 were separately added to separate aqueous solutions containing X –, Y – and Z – ions. X –(aq) Y –(aq) Z –(aq) X2(aq) no reaction no reaction no reaction Y2(aq) X2 formed no reaction Z2 formed Z2(aq) X2 formed no reaction no reaction Which row in the following table contains the ions X –, Y – and Z – in order of their decreasing strength as reducing agents? strongest weakest A X – Y – Z – B X – Z – Y – C Y – Z – X – D Z – X – Y –

1 marks

Answer: B

This question in 9701/11 May/June 2011

36 Use of the Data Booklet is relevant to this question. The element astatine lies below iodine in Group VII of the Periodic Table. What will be the properties of astatine? 1 It forms diatomic molecules which dissociate more readily than chlorine molecules. 2 It reacts explosively with hydrogen. 3 It can oxidise iodide to iodine.

1 marks

Answer: D

This question in 9701/11 May/June 2011

16 X, Y and Z represent different halogens. The table shows the results of nine experiments in which aqueous solutions of X2, Y2 and Z2 were separately added to separate aqueous solutions containing X –, Y – and Z – ions. X –(aq) Y –(aq) Z –(aq) X2(aq) no reaction no reaction no reaction Y2(aq) X2 formed no reaction Z2 formed Z2(aq) X2 formed no reaction no reaction Which row in the following table contains the ions X –, Y – and Z – in order of their decreasing strength as reducing agents? strongest weakest A X – Y – Z – B X – Z – Y – C Y – Z – X – D Z – X – Y –

1 marks

Answer: B

This question in 9701/13 May/June 2011

17 A student observed the reactions when sodium chloride and sodium iodide were each reacted separately with concentrated sulfuric acid and with concentrated phosphoric acid. The observations are recorded in the table. sodium chloride sodium iodide conc. H2SO4 colourless acidic gas formed purple vapour formed conc. H3PO4 colourless acidic gas formed colourless acidic gas formed Which deduction can be made from these observations? A Concentrated phosphoric acid is a stronger oxidising agent than concentrated sulfuric acid. B Concentrated phosphoric acid is a stronger oxidising agent than iodine. C Concentrated sulfuric acid is a stronger oxidising agent than chlorine. D Concentrated sulfuric acid is a stronger oxidising agent than iodine.

1 marks

Answer: D

This question in 9701/13 May/June 2011

35 Use of the Data Booklet is relevant to this question. The element astatine lies below iodine in Group VII of the Periodic Table. What will be the properties of astatine? 1 It forms diatomic molecules which dissociate more readily than chlorine molecules. 2 It reacts explosively with hydrogen. 3 It can oxidise iodide to iodine.

1 marks

Answer: D

This question in 9701/13 May/June 2011

17 The standard enthalpy changes of formation of HCl and HI are –92 kJ mol–1 and +26 kJ mol–1 respectively. Which statement is most important in explaining this difference? A Chlorine is more electronegative than iodine. B The activation energy for the H2 + Cl2 reaction is much less than that for the H2 + I2 reaction. C The bond energy of HI is smaller than the bond energy of HCl. D The bond energy of I2 is smaller than the bond energy of Cl2.

1 marks

This question in 9701/12 Oct/Nov 2011

17 What trend is observed on descending Group VII? A The colours of the elements become lighter. B The elements become more volatile. C The hydrides of the elements become more thermally stable. D The reactions of the elements with hydrogen become less vigorous.

1 marks

Answer: D

This question in 9701/11 May/June 2012

18 The following two experiments are carried out with anhydrous potassium chloride and observations X and Y are made at the end of each experiment. Concentrated sulfuric acid is added to the potassium chloride and the fumes produced are bubbled into aqueous potassium iodide solution - observation X. The potassium chloride is dissolved in aqueous ammonia and this is then added to aqueous silver nitrate - observation Y. What are the observations X and Y? X Y A brown solution colourless solution B brown solution white precipitate C colourless solution colourless solution D colourless solution white precipitate

1 marks

Answer: C

This question in 9701/11 May/June 2012

35 Which statements are correct for all three halogens, chlorine, bromine and iodine? 1 They all form hydrides that are strong acids in aqueous solution. 2 They all react with aqueous sodium hydroxide to form oxo-anions. 3 They all require one more electron to fill the p orbitals of their outer shells.

1 marks

Answer: A

This question in 9701/11 May/June 2012

16 Chlorine shows oxidation states ranging from –1 to +7 in its compounds. What are the reagent(s) and conditions necessary for the oxidation of elemental chlorine into a compound containing chlorine in the +5 oxidation state? A AgNO3(aq) followed by NH3(aq) at room temperature B concentrated H2SO4 at room temperature C cold dilute NaOH(aq) D hot concentrated NaOH(aq)

1 marks

Answer: D

This question in 9701/12 May/June 2012

18 What trend is observed on descending Group VII? A The colours of the elements become lighter. B The elements become more volatile. C The hydrides of the elements become more thermally stable. D The reactions of the elements with hydrogen become less vigorous.

1 marks

Answer: D

This question in 9701/13 May/June 2012

34 Which statements are correct for all three halogens, chlorine, bromine and iodine? 1 They all form hydrides that are strong acids in aqueous solution. 2 They all react with aqueous sodium hydroxide to form oxo-anions. 3 They all require one more electron to fill the p orbitals of their outer shells.

1 marks

Answer: A

This question in 9701/13 May/June 2012

34 The element astatine, At, is below iodine in Group VII of the Periodic Table. Which statements concerning At will be correct? 1 It is a dark-coloured solid at room temperature. 2 It is a more powerful oxidising agent than iodine. 3 Its hydride is thermally stable.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2012

34 The element astatine, At, is below iodine in Group VII of the Periodic Table. Which statements concerning At will be correct? 1 It is a dark-coloured solid at room temperature. 2 It is a more powerful oxidising agent than iodine. 3 Its hydride is thermally stable.

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2012

15 The reaction between KI and concentrated H2SO4 is a redox reaction. 5H2SO4 + 8KI → 4K2SO4 + 4I2 + H2S + 4H2O What is the change in oxidation state of the element that is reduced? A 1 B 4 C 6 D 8

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2012

36 The table describes some of the chemistry and thermodynamic properties of the halogens. name and process symbol of quantity 2HX(g) → H2(g) + X2(g) enthalpy change of reaction, H2(g) + X2(g) 2HX(g) equilibrium constant, Kp X(g) → X+(g) + e– ionisation energy, Which statements about the relative values of these quantities are correct? 1 for HCl > for HBr 2 Kp for HBr > Kp for HI 3 for I > for Cl

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2012

14 What happens when iodine solution is added to a solution of sodium bromide? A A reaction occurs without changes in oxidation state. B Bromide ions are oxidised, iodine atoms are reduced. C Bromide ions are reduced, iodine atoms are oxidised. D No reaction occurs.

1 marks

Answer: D

This question in 9701/11 May/June 2013

15 Element 85, astatine, is in Group VII. Concentrated sulfuric acid is added to sodium astatide. The mixture of products includes astatine, hydrogen astatide, hydrogen sulfide, and sodium sulfate. Which product is formed by the oxidation of one of the constituents of sodium astatide? A astatine B hydrogen astatide C hydrogen sulfide D sodium sulfate

1 marks

Answer: A

This question in 9701/11 May/June 2013

36 When a red-hot platinum wire is plunged into a test tube of hydrogen iodide, the gas is decomposed into its elements. If the experiment is repeated with hydrogen chloride, no change occurs. Which factors contribute to this behaviour? 1 the strength of the hydrogen-halogen bond 2 the size of the halogen atom 3 the standard enthalpy of formation, , of each of the products of decomposition

1 marks

Answer: B

This question in 9701/11 May/June 2013

18 What happens when bromine solution is added to a solution of sodium iodide? A A reaction occurs without changes in oxidation state. B Bromine atoms are oxidised, iodide ions are reduced. C Bromine atoms are reduced, iodide ions are oxidised. D No reaction occurs.

1 marks

Answer: C

This question in 9701/12 May/June 2013

35 Which properties increase in the sequence hydrogen chloride, hydrogen bromide and hydrogen iodide? 1 thermal stability 2 bond length 3 ease of oxidation

1 marks

Answer: C

This question in 9701/12 May/June 2013

14 Two students, P and Q, were asked to draw bar charts to represent how some properties of the halogens and their compounds differ in magnitude. Their diagrams are shown. student P student Q ∆H o I Cl Br I 0 solubility Br Cl 0 solubility of AgX(s) in NH3(aq) ∆H o for H2(g) + X2(g) → 2HX(g) Which of the student’s diagrams are correct? A both P and Q B P only C Q only D neither P nor Q

1 marks

Answer: C

This question in 9701/13 May/June 2013

12 Redox reactions occur very frequently in the chemistry of Group VII. Which statement is correct? A Chlorine will oxidise bromide ions but not iodide ions. B Fluorine is the weakest oxidising agent out of F2, Cl 2, Br2 and I2. C Iodide ions are the weakest reducing agent out of F –, Cl –, Br – and I –. D When chlorine reacts with water, chlorine is both oxidised and reduced.

1 marks

Answer: D

This question in 9701/11 May/June 2014

36 A test-tube of HI gas and a test-tube of HBr gas are placed together in an environment at temperature, T. Which combinations of observations are possible depending on the temperature, T? 1 A brown vapour appears in one of the test-tubes. No change is apparent in the other test-tube. 2 A brown vapour appears in one of the test-tubes. A purple vapour appears in the other test-tube. 3 No change is apparent in either test-tube.

1 marks

Answer: C

This question in 9701/11 May/June 2014

18 A test-tube of HBr(g) and a test-tube of HI(g) are heated to the same temperature. Which combination of observations is possible? tube of HBr(g) tube of HI(g) A a brown vapour appears no change is apparent B a purple vapour appears no change is apparent C no change is apparent a brown vapour appears D no change is apparent a purple vapour appears

1 marks

Answer: D

This question in 9701/12 May/June 2014

17 Under standard conditions, which statement is correct? A Cl –(aq) can oxidise Br2(aq). B Cl –(aq) can reduce Br2(aq). C Cl 2(aq) can oxidise Br –(aq). D Cl 2(aq) can reduce Br –(aq).

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2014

35 On being heated, hydrogen iodide breaks down more quickly than hydrogen chloride. Which statements explain this faster rate? 1 The HI bond is weaker than the HCl bond. 2 The reaction of the breakdown of HI has a smaller activation energy than that of HCl. 3 The breakdown of HI is more exothermic than that of HCl.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2014

32 Use of the Data Booklet is relevant to this question. The bond energy of the Br – O bond is 235 kJ mol–1. Which reactions are exothermic? 1 OH• + HBr → H2 + BrO• 2 OH• + HBr → H2O + Br• 3 H• + HBr → H2 + Br•

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2014

35 On being heated, hydrogen iodide breaks down more quickly than hydrogen chloride. Which statements explain this faster rate? 1 The HI bond is weaker than the HCl bond. 2 The reaction of the breakdown of HI has a smaller activation energy than that of HCl. 3 The breakdown of HI is more exothermic than that of HCl.

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2014

2 Which quantity gives the best indication of the relative strengths of the hydrogen bonds between the molecules in liquid hydrogen halides? A bond dissociation energies B enthalpy changes of formation C enthalpy changes of solution D enthalpy changes of vaporisation

1 marks

Answer: D

This question in 9701/11 May/June 2015

17 Astatine, At, is below iodine in Group VII of the Periodic Table. Which statement is most likely to be correct? A AgAt(s) reacts with excess dilute aqueous ammonia to form a solution of a soluble complex. B Astatine and KCl (aq) react to form KAt(aq) and chlorine. C KAt(aq) and dilute sulfuric acid react to form white fumes of HAt(g). D NaAt(s) and concentrated sulfuric acid react to form astatine.

1 marks

Answer: D

This question in 9701/11 May/June 2015

17 A student observed the reactions when sodium chloride and sodium iodide were each reacted separately with concentrated sulfuric acid and with concentrated phosphoric acid. Some observations are recorded in the table. sodium chloride sodium iodide conc. H2SO4 colourless acidic gas formed purple vapour formed conc. H3PO4 colourless acidic gas formed colourless acidic gas formed Which deduction can be made from these observations? A Concentrated phosphoric acid is a stronger oxidising agent than concentrated sulfuric acid. B Concentrated phosphoric acid is a stronger oxidising agent than iodine. C Concentrated sulfuric acid is a stronger oxidising agent than chlorine. D Concentrated sulfuric acid is a stronger oxidising agent than iodine.

1 marks

This question in 9701/12 Oct/Nov 2015

16 Hydrogen chloride gas and hydrogen iodide gas have different thermal stabilities. The difference is due to a difference in the energies of some of the covalent bonds that are involved in the decomposition. Which row identifies the more stable of the two compounds, and gives the correct explanation? identity of the more explanation for the thermally stable compound difference in stability A hydrogen chloride the Cl–Cl bond is stronger than the I–I bond B hydrogen chloride the H–Cl bond is stronger than the H–I bond C hydrogen iodide the Cl –Cl bond is stronger than the I–I bond D hydrogen iodide the H–Cl bond is stronger than the H–I bond

1 marks

Answer: B

This question in 9701/12 Feb/March 2016

35 The element astatine, At, is below iodine in Group 17 of the Periodic Table. Which statements concerning At are likely to be correct? 1 It is a dark-coloured solid at room temperature. 2 It is a more powerful oxidising agent than iodine. 3 Its hydride is thermally stable.

1 marks

Answer: D

This question in 9701/11 May/June 2016

36 Which properties increase in the sequence hydrogen chloride, hydrogen bromide and hydrogen iodide? 1 thermal stability 2 bond length 3 ease of oxidation

1 marks

Answer: C

This question in 9701/12 May/June 2016

17 Two students, P and Q, were asked to draw bar charts to represent how some properties of the halogens and their compounds differ in magnitude. Their diagrams are shown. The bar charts show trends only and not actual values. student P student Q ∆H o I Cl Br I 0 solubility Br Cl 0 solubility of AgX(s) in NH3(aq) ∆H o for H2(g) + X2(g) → 2HX(g) Which of the students have drawn bar charts which show the trends correctly? A both P and Q B P only C Q only D neither P nor Q

1 marks

Answer: C

This question in 9701/13 May/June 2016

18 In a series of nine experiments to test the reactivity of the halogens, an aqueous solution of each halogen was added to an equal volume of an aqueous solution containing halide ions as shown in the table below. solution sodium chloride (aq) sodium bromide (aq) sodium iodide (aq) chlorine (aq) experiment 1 experiment 2 experiment 3 bromine (aq) experiment 4 experiment 5 experiment 6 iodine (aq) experiment 7 experiment 8 experiment 9 The nine resulting mixtures were then shaken with hexane. The nine tubes were corked and left to stand so that the aqueous and organic solvents could separate into layers. How many test-tubes contained a purple upper layer? A 1 B 2 C 3 D 5

1 marks

Answer: D

This question in 9701/13 May/June 2016

19 X, Y and Z represent different halogens. The table shows the results of nine experiments in which aqueous solutions of X2, Y2 and Z2 were separately added to separate aqueous solutions containing X –, Y – and Z – ions. X –(aq) Y –(aq) Z –(aq) X2(aq) no reaction no reaction no reaction Y2(aq) X2 formed no reaction Z2 formed Z2(aq) X2 formed no reaction no reaction Which row of the following table contains the ions X –, Y – and Z – in order of their decreasing strength as reducing agents? strongest weakest A X – Y – Z – B X – Z – Y – C Y – Z – X – D Z – X – Y –

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2016

19 X, Y and Z represent different halogens. The table shows the results of nine experiments in which aqueous solutions of X2, Y2 and Z2 were separately added to separate aqueous solutions containing X –, Y – and Z – ions. X –(aq) Y –(aq) Z –(aq) X2(aq) no reaction no reaction no reaction Y2(aq) X2 formed no reaction Z2 formed Z2(aq) X2 formed no reaction no reaction Which row of the following table contains the ions X –, Y – and Z – in order of their decreasing strength as reducing agents? strongest weakest A X – Y – Z – B X – Z – Y – C Y – Z – X – D Z – X – Y –

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2016

17 A test-tube of HBr(g) and a separate test-tube of HI(g) are heated to the same temperature. Which combination of observations is possible? test-tube of HBr(g) test-tube of HI(g) A a brown vapour appears no change B a purple vapour appears no change C no change a brown vapour appears D no change a purple vapour appears

1 marks

Answer: D

This question in 9701/13 May/June 2017

17 Sodium bromide reacts with concentrated sulfuric acid. Which observation will be made? A A coloured vapour is produced. B A purple solid is formed. C A strong smell of H2S is detected. D Yellow sulfur is formed.

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2017

17 Bromine is extracted from sea-water. In the final stages of the process two redox reactions take place. Br2(aq) + SO2(g) + 2H2O(l) → 2HBr(aq) + H2SO4(aq) 2HBr(aq) + Cl 2(g) → Br2(g) + 2HCl (aq) Which row is correct? strongest weakest oxidising agent oxidising agent A Br2 SO2 Cl 2 B Cl 2 Br2 SO2 C Cl 2 SO2 Br2 D SO2 Br2 Cl 2

1 marks

Answer: B

This question in 9701/12 Feb/March 2018

17 When concentrated sulfuric acid is added to solid sodium bromide, bromine gas is produced, along with a number of other products. However when concentrated sulfuric acid is added to solid sodium chloride only hydrogen chloride and sodium hydrogensulfate are produced. What is the reason for this difference? A Bromine is less volatile than chlorine. B Hydrochloric acid is a weak acid. C Sulfuric acid is not an oxidising agent. D The bromide ion is a stronger reducing agent than the chloride ion.

1 marks

Answer: D

This question in 9701/12 May/June 2018

16 When concentrated sulfuric acid is added to solid sodium chloride, HCl is formed but not Cl 2. When concentrated sulfuric acid is added to solid sodium iodide, I2 is formed. Which statement explains these observations? A Sulfuric acid is an oxidising agent and chloride ions are more easily oxidised. B Sulfuric acid is an oxidising agent and iodide ions are more easily oxidised. C Sulfuric acid is a reducing agent and chloride ions are more easily reduced. D Sulfuric acid is a reducing agent and iodide ions are more easily reduced.

1 marks

Answer: B

This question in 9701/13 May/June 2018

16 Which statement about the halogens is correct? A Iodine cannot behave as an oxidising agent. B The volatility of the elements increases from chlorine to iodine because of the increase in molecular size down the group. C When an equimolar mixture of chlorine and hydrogen is exploded, only one product is formed. D When concentrated sulfuric acid is added to solid sodium bromide, hydrogen sulfide is one of the products.

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2018

18 Under standard conditions, which statement is correct? A Cl 2(aq) can oxidise Br –(aq). B Cl 2(aq) can reduce Br –(aq). C Cl –(aq) can oxidise Br2(aq). D Cl –(aq) can reduce Br2(aq).

1 marks

Answer: A

This question in 9701/12 Feb/March 2019

16 The solids sodium chloride and sodium iodide both react with concentrated sulfuric acid at room temperature. With NaCl , the products are NaHSO4 and HCl . With NaI, the products are NaHSO4, HI, I2, SO2, H2O, S and H2S. What is the explanation for this difference in products? A Chloride ions will displace iodine from solution. B Hydrogen chloride is more volatile than hydrogen iodide. C Iodide ions are better reducing agents than chloride ions. D Sulfuric acid is able to act as a dehydrating agent with NaI.

1 marks

Answer: C

This question in 9701/13 May/June 2019

35 Which statements about sodium chloride are correct? 1 It is a product of the reaction between chlorine and cold aqueous sodium hydroxide. 2 It is a product of the reaction between chlorine and hot aqueous sodium hydroxide. 3 It is a product of the reaction between chlorine and aqueous sodium bromide.

1 marks

Answer: A

This question in 9701/13 May/June 2019

17 Sodium azide, NaN3, is dissolved in water. Acidified silver nitrate is added to the solution and a white precipitate forms. Aqueous ammonia is then added to the white precipitate. The azide ion, N3 –, has similar chemical properties to the Cl – ion. Which row of the table can be predicted from this information? formula of observation on adding white precipitate aqueous ammonia A AgN3 colourless solution formed B AgN3 precipitate remains C Ag3N colourless solution formed D Ag3N precipitate remains

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2019

18 How does concentrated sulfuric acid behave when it reacts with sodium chloride? A as an acid only B as an acid and oxidising agent C as an oxidising agent only D as a reducing agent only

1 marks

Answer: A

This question in 9701/12 Feb/March 2020

35 The element astatine, At, is below iodine in Group 17 of the Periodic Table. Which statements concerning At are likely to be correct? 1 It is a dark-coloured solid at room temperature. 2 It is a more powerful oxidising agent than iodine. 3 Its hydride is more thermally stable than HBr.

1 marks

Answer: D

This question in 9701/12 Feb/March 2020

18 Astatine, At, is below iodine in Group 17 of the Periodic Table. Which statement is most likely to be correct? A AgAt(s) reacts with an excess of dilute aqueous ammonia to form a solution of a soluble complex. B Astatine and KCl (aq) react to form KAt(aq) and chlorine. C KAt(aq) and dilute sulfuric acid react to form HAt(g). D NaAt(s) and concentrated sulfuric acid react to form astatine.

1 marks

Answer: D

This question in 9701/11 May/June 2020

18 A test-tube of HBr(g) and a separate test-tube of HI(g) are heated to the same temperature. Which combination of observations is possible? test-tube of HBr(g) test-tube of HI(g) A a brown vapour appears no change B a purple vapour appears no change C no change a brown vapour appears D no change a purple vapour appears

1 marks

Answer: D

This question in 9701/12 May/June 2020

36 The bond … P … of the HBr molecule is … Q … than that of the HI molecule. Which pairs of words correctly complete the above sentence? P Q 1 energy greater 2 length less 3 polarity greater

1 marks

Answer: A

This question in 9701/12 May/June 2020

16 With which compound does concentrated sulfuric acid react both as a strong acid and as an oxidising agent? A magnesium carbonate B potassium chloride C sodium bromide D sulfur trioxide

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2020

17 Which statement about Group 17 elements and their compounds is correct? A Chlorine reacts with cold concentrated sodium hydroxide to form NaCl and NaCl O3. B HCl is more thermally stable than HBr because chlorine is less electronegative than bromine. C Iodide ions are oxidised to iodine by concentrated sulfuric acid. D Silver iodide is soluble in dilute aqueous ammonia.

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2020

16 With which compound does concentrated sulfuric acid react both as a strong acid and as an oxidising agent? A magnesium carbonate B potassium chloride C sodium bromide D sulfur trioxide

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2020

17 When concentrated sulfuric acid reacts with sodium iodide the products include sulfur, iodine, hydrogen sulfide and sulfur dioxide. Which statement is correct? A Hydrogen sulfide is the product of a reduction reaction. B Iodide ions are stronger oxidising agents than sulfate ions. C Sulfur atoms from the sulfuric acid are both oxidised and reduced. D Sulfur atoms from the sulfuric acid are oxidised to make sulfur dioxide.

1 marks

Answer: A

This question in 9701/12 Feb/March 2021

9 When hydrogen iodide is reacted with concentrated sulfuric acid, several reactions occur, including: 8HI + H2SO4  H2S + 4H2O + 4I2 Which row gives the change in oxidation number of iodine and of sulfur in this reaction? change in oxidation change in oxidation number of iodine number of sulfur A –1 +6 B –1 +8 C +1 –6 D +1 –8

1 marks

Answer: D

This question in 9701/11 May/June 2021

16 In a series of nine experiments, to test the reactivity of the halogens, an aqueous solution of each halogen is added to an equal volume of an aqueous solution containing halide ions, as shown in the table. halogen halide solution solution sodium chloride (aq) sodium bromide (aq) sodium iodide (aq) chlorine (aq) experiment 1 experiment 2 experiment 3 bromine (aq) experiment 4 experiment 5 experiment 6 iodine (aq) experiment 7 experiment 8 experiment 9 The nine resulting mixtures are then shaken separately with an equal volume of hexane. The nine tubes are left to stand so that the aqueous and organic solvents separate into layers. How many test-tubes contain a purple upper hexane layer? A 1 B 2 C 3 D 5

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2021

15 Redox reactions are common in the chemistry of Group 17 elements. Which statement is correct? A Br – ions will reduce Cl 2 but not I2. B Cl 2 will oxidise Br – ions but not I– ions. C F2 is the weakest oxidising agent out of F2, Cl 2, Br2 and I2. D I– ions are the weakest reducing agent out of F –, Cl –, Br – and I–.

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2021

16 In a series of nine experiments, to test the reactivity of the halogens, an aqueous solution of each halogen is added to an equal volume of an aqueous solution containing halide ions, as shown in the table. halogen halide solution solution sodium chloride (aq) sodium bromide (aq) sodium iodide (aq) chlorine (aq) experiment 1 experiment 2 experiment 3 bromine (aq) experiment 4 experiment 5 experiment 6 iodine (aq) experiment 7 experiment 8 experiment 9 The nine resulting mixtures are then shaken separately with an equal volume of hexane. The nine tubes are left to stand so that the aqueous and organic solvents separate into layers. How many test-tubes contain a purple upper hexane layer? A 1 B 2 C 3 D 5

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2021

12 In the treatment of domestic water supplies, chlorine is added to water to kill bacteria. Some Cl O– ions are formed. What is the change in oxidation number of chlorine when forming the Cl O– ion from aqueous chlorine? A –1 B 0 C +1 D +2

1 marks

Answer: C

This question in 9701/11 May/June 2022

25 Which reaction mixture produces an acidic gas? A aqueous ammonium nitrate and solid calcium oxide B calcium and aqueous hydrochloric acid C potassium chloride and concentrated sulfuric acid D sodium oxide and water

1 marks

Answer: C

This question in 9701/11 May/June 2022

22 X, Y and Z are three elements in Group 17. X2 has weaker covalent bonds than Y2. X2 has stronger instantaneous dipole–induced dipole forces between its molecules than Z2. Y2 is a stronger oxidising agent than Z2. What could be X, Y and Z? X Y Z A Br Cl I B Cl Br I C I Br Cl D I Cl Br

1 marks

Answer: D

This question in 9701/12 May/June 2022

22 Chlorine is bubbled through a cylinder containing aqueous sodium iodide and an immiscible layer of hexane. excess gas out chlorine gas hexane aqueous sodium iodide As the bubbles pass through the cylinder, what is observed in the lower and upper layers? lower aqueous layer upper hexane layer A colourless solution becomes brown colourless liquid becomes coloured B colourless solution becomes brown colourless liquid is unchanged C brown solution becomes colourless colourless liquid becomes coloured D brown solution becomes colourless colourless liquid is unchanged

1 marks

Answer: A

This question in 9701/13 May/June 2022

21 Which statement about Group 17 elements and compounds is correct? A Sodium chloride produces chlorine when reacted with concentrated sulfuric acid. B Sodium chloride produces chlorine when reacted with bromine. C Sodium bromide produces bromine when reacted with concentrated sulfuric acid. D Sodium bromide produces bromine when reacted with iodine in aqueous potassium iodide.

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2022

21 Which statement about Group 17 elements and compounds is correct? A Sodium chloride produces chlorine when reacted with concentrated sulfuric acid. B Sodium chloride produces chlorine when reacted with bromine. C Sodium bromide produces bromine when reacted with concentrated sulfuric acid. D Sodium bromide produces bromine when reacted with iodine in aqueous potassium iodide.

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2022

24 Which statement about the halogens is correct? A Iodine cannot behave as an oxidising agent. B The volatility of the elements increases from chlorine to iodine because of the increase in molecular size down the group. C When an equimolar mixture of chlorine and hydrogen is exploded, only one product is formed. D When concentrated sulfuric acid is added to solid sodium bromide, hydrogen sulfide is one of the products.

1 marks

Answer: C

This question in 9701/13 May/June 2023

23 Which statement about the halogens or halide ions is correct? A Bromide ions react to form a white precipitate when added to silver nitrate solution. B Bromine does not oxidise chloride ions when added to sodium chloride solution. C Fluorine atoms form cations by accepting electrons when they react. D Chloride ions are stronger reducing agents than iodide ions.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2023

12 Chlorine reacts with sodium bromide. Cl 2 + NaBr →NaCl + Br2 Which words correctly describe this reaction? 1 redox 2 displacement 3 disproportionation A 1, 2 and 3 B 1 and 2 only C 1 only D 2 only

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2023

25 When concentrated sulfuric acid is added to solid sodium chloride, HCl is formed but not Cl 2. When concentrated sulfuric acid is added to solid sodium iodide, I2 is formed. Which statement explains these observations? A Sulfuric acid is an oxidising agent and chloride ions are more easily oxidised than iodide ions. B Sulfuric acid is an oxidising agent and iodide ions are more easily oxidised than chloride ions. C Sulfuric acid is a reducing agent and chloride ions are more easily reduced than iodide ions. D Sulfuric acid is a reducing agent and iodide ions are more easily reduced than chloride ions.

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2023

23 Which statement about the halogens or halide ions is correct? A Bromide ions react to form a white precipitate when added to silver nitrate solution. B Bromine does not oxidise chloride ions when added to sodium chloride solution. C Fluorine atoms form cations by accepting electrons when they react. D Chloride ions are stronger reducing agents than iodide ions.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2023

21 This question is about two salts, NaI and NaCl. The two solid salts are separately added to warm concentrated H2SO4 and the results noted. Aqueous solutions of the two salts are separately added to AgNO3(aq) and then concentrated NH3(aq) is added and the results noted. Which row is correct? identity of one product formed observation after AgNO3(aq) salt with concentrated H2SO4 and NH3(aq) are added A NaCl Cl 2 colourless solution B NaCl H2S white precipitate C NaI H2S yellow precipitate D NaI I2 colourless solution

1 marks

Answer: C

This question in 9701/12 Feb/March 2024

21 The table shows statements about some of the properties of halogens and their compounds and explanations for these properties. Which row shows a correct statement about the property and a correct explanation for the statement? statement explanation A iodine is a solid at room temperature the I–I bond strength is high B the decomposition of hydrogen iodide chlorine is more is more endothermic than the reactive than iodine decomposition of hydrogen chloride C when chlorine is bubbled into aqueous chlorine is a stronger potassium iodide, a purple solution is seen oxidising agent than iodine D when concentrated sulfuric acid is added to iodide ions are being oxidised solid potassium iodide, a purple vapour is seen to iodine by the sulfuric acid

1 marks

Answer: D

This question in 9701/12 May/June 2024

21 Which statement is correct? A Hydrogen bromide reduces concentrated sulfuric acid to form sulfur dioxide gas. B Hydrogen bromide decomposes at a higher temperature than hydrogen chloride. C When hydrogen bromide gas is shaken with aqueous silver nitrate a yellow precipitate is formed. D When hydrogen bromide gas is bubbled through aqueous iodine the solution becomes colourless.

1 marks

Answer: A

This question in 9701/13 May/June 2024

22 ICl is made when Cl 2 and I2 react together. Cl 2 + I2 2ICl ICl reacts with water. 5ICl + 3H2O  5HCl + HIO3 + 2I2 Which row is correct? oxidation number reaction occurring of I in ICl when ICl reacts with H2O A +1 the iodine atoms are oxidised to form I2 B +1 the iodine atoms are oxidised to form HIO3 C –1 the chlorine atoms are reduced to form HCl D –1 the iodine atoms are oxidised to form HIO3

1 marks

Answer: B

This question in 9701/13 May/June 2024

21 In reaction 1, concentrated sulfuric acid is added to potassium chloride and the fumes produced are bubbled into aqueous potassium iodide solution. In reaction 2, potassium chloride is dissolved in aqueous ammonia and this is then added to aqueous silver nitrate. What are the observations for reactions 1 and 2? observation for observation for reaction 1 reaction 2 A brown solution colourless solution B brown solution white precipitate C colourless solution colourless solution D colourless solution white precipitate

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2024

22 The table refers to the hydrogen halides. Which row is correct? oxidation thermal stability A easier to oxidise down the group increases down the group B more difficult to oxidise down the group increases down the group C easier to oxidise down the group decreases down the group D more difficult to oxidise down the group decreases down the group

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2024

22 The table refers to the hydrogen halides. Which row is correct? oxidation thermal stability A easier to oxidise down the group increases down the group B more difficult to oxidise down the group increases down the group C easier to oxidise down the group decreases down the group D more difficult to oxidise down the group decreases down the group

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2024

19 U, V and W represent different halogens. The table shows the results of nine experiments in which aqueous solutions of U2, V2 and W2 were separately added to separate aqueous solutions containing U–, V – and W – ions. U–(aq) V –(aq) W –(aq) U2(aq) no reaction no reaction no reaction V2(aq) U2 formed no reaction W2 formed W2(aq) U2 formed no reaction no reaction Which row contains the ions U–, V – and W – in order of their decreasing strength as reducing agents? strongest weakest A U– V – W – B U– W – V – C V – W – U– D W – U– V –

1 marks

Answer: B

This question in 9701/12 Feb/March 2025

18 Three statements about the halogens, chlorine, bromine and iodine and their compounds are listed. 1 The halogen with the highest boiling point has atoms which form the strongest bond to hydrogen. 2 The halogen with the strongest instantaneous dipole (id–id) attractions forms the most thermally stable hydrogen halide. 3 The most volatile element most rapidly oxidises hydrogen. Which statements are correct? A 1 and 2 B 1 only C 2 and 3 D 3 only

1 marks

Answer: D

This question in 9701/11 May/June 2025

20 Sodium bromide is warmed with concentrated sulfuric acid. Which row describes the change in the oxidation number of the sulfur and the role of the bromide ions in the reaction? change in role of oxidation number bromide ions of sulfur A +6 to +4 oxidising agent B +6 to +4 reducing agent C +4 to 0 oxidising agent D +4 to 0 reducing agent

1 marks

Answer: B

This question in 9701/12 May/June 2025

19 Which statement about the properties of halogens and hydrogen halides is correct? A A chloride ion is a stronger reducing agent than an iodide ion. B Chlorine is more volatile than bromine because chlorine has stronger intermolecular forces. C Hydrogen bromide is more thermally stable than hydrogen iodide because it has a stronger covalent bond. D Iodine is less reactive than bromine because iodine has weaker covalent bonds.

1 marks

Answer: C

This question in 9701/13 May/June 2025

21 Equation 1 and equation 2 show two different reactions of halide ion Q– with concentrated sulfuric acid. equation 1 H2SO4 + Q– HSO4 – + HQ equation 2 H2SO4 + 2Q– + 2H+ SO2 + Q2 + 2H2O What is Q? A Cl– or Br– B Br– or I– C Cl– only D I– only

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2025

22 What happens when iodine solution is added to a solution of sodium bromide? A A reaction occurs without changes in oxidation state. B Bromide ions are oxidised; iodine atoms are reduced. C Bromide ions are reduced; iodine atoms are oxidised. D No reaction occurs.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2025

22 X and Y are sodium salts of Group 17 elements. When X reacts with concentrated sulfuric acid, hydrogen sulfide, H2S, is produced. When Y reacts with concentrated sulfuric acid, there is no change in the oxidation number of the sulfur. Which statement is correct? A Aqueous X reduces aqueous bromine. B Aqueous Y reacts with aqueous silver nitrate to give a precipitate which is insoluble in concentrated aqueous ammonia. C X and Y react separately with concentrated sulfuric acid to produce halogens. D When X reacts with concentrated sulfuric acid, six halide ions are needed to reduce one sulfur atom to H2S.

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2025