Chemistry 9701 · AS & A Level
Group 17
100 practice questions on Group 17, with worked solutions and instant marking.
Hydrogen chloride gas and hydrogen iodide gas do not have the same thermal stability. This difference arises because some of the covalent bonds involved in decomposition have different bond energies. Which row identifies which of the two compounds is the more stable, and provides the correct reason?
Feb/March 2016
Several uses of chlorine and bromine are listed below. Which one is a use of bromine?
Feb/March 2017
Hydrogen halides are compounds produced when halogens (Group 17 elements) react with hydrogen. The bond polarity of the hydrogen halides decreases from HF to HI. Some relevant data are shown in the table.
Feb/March 2017
The table summarises some reactions of a white compound, G. When silver nitrate is added to a solution of G, and then aqueous ammonia is added, a precipitate appears and it does not dissolve after the ammonia is added. When solid G is heated with concentrated sulfuric acid, a gaseous mixture is produced that includes hydrogen sulfide. What could G be?
Feb/March 2019
The element astatine, At, lies beneath iodine in Group 17 of the Periodic Table. Which of the following statements about At are likely to be true?
Feb/March 2020
The Group 17 elements chlorine, bromine and iodine are non-metals, and their physical and chemical properties follow clear trends.
Feb/March 2020
Chlorine, $\text{Cl}_2$, is a reactive yellow-green gas. It is a powerful oxidising agent.
Feb/March 2021
Which of the following statements about the elements in Group 17 and their compounds is correct?
Feb/March 2022
At room temperature, the hydrogen halides HCl, HBr and HI are all colourless gases.
Feb/March 2022
Powder P is a mixture of two substances chosen from $\text{AgCl}$, $\text{AgBr}$ and $\text{AgI}$. P is shaken with dilute aqueous ammonia. A yellow solid, Q, is left behind. The mixture is then filtered, and Q is rinsed and dried. The filtrate is gathered and added to aqueous nitric acid to form a white precipitate, R, which is filtered off, washed and dried. Q and R are each warmed separately with concentrated sulfuric acid, $\text{H}_2\text{SO}_4$. Which observations are made?
Feb/March 2023
This question concerns two salts, NaI and NaCl. Each of the two solid salts is added separately to warm concentrated $\text{H}_2\text{SO}_4$, and the observations are recorded. Aqueous solutions of the two salts are each mixed separately with $\text{AgNO}_3$(aq), after which concentrated $\text{NH}_3$(aq) is added, and the observations are recorded. Which row is correct?
Feb/March 2024
Chlorine, Cl$_2$, takes part in reactions with many elements and compounds, producing chlorides. Table 2.1 gives details of some chlorides of Period 3 elements.
Feb/March 2024
The equation for a reaction involving $\text{KClO}_3$ is given below. $4\text{KClO}_3 \rightarrow \text{KCl} + 3\text{KClO}_4$ Which row is correct?
Feb/March 2025
Which graph correctly shows a trend observed in Group 17? [X stands for a halogen atom.]
Feb/March 2025
Phosphorus and chlorine are both elements in Period 3 of the Periodic Table.
Feb/March 2025
The halogens chlorine, bromine and iodine display patterns in chemical and physical properties down the group. Table 3.1 gives some properties of chlorine, bromine and iodine.
Feb/March 2025
What occurs when concentrated sulfuric acid reacts with sodium chloride?
May/June 2010
What happens when concentrated sulfuric acid reacts with sodium chloride?
May/June 2010
X is a salt of a halogen such as chlorine, bromine, iodine, or astatine (proton number 85). The reaction scheme below shows a sequence of reactions, with a solution of X used as the initial reagent. $X \xrightarrow[\text{AgNO}_3\text{(aq)}]{\text{HNO}_3\text{(aq)}}$ a precipitate $\xrightarrow{\text{an excess of dilute NH}_3\text{(aq)}}$ a colourless solution $\xrightarrow{\text{an excess of HNO}_3\text{(aq)}}$ a precipitate What might X be?
May/June 2010
The element astatine is located beneath iodine in Group VII of the Periodic Table. What properties would astatine have?
May/June 2011
A student watched what happened when sodium chloride and sodium iodide were reacted separately with concentrated sulfuric acid and with concentrated phosphoric acid. The observations are shown in the table. Which conclusion can be drawn from these observations?
May/June 2011
The Data Booklet may be needed for this question. The element astatine is placed below iodine in Group VII of the Periodic Table. What properties would astatine show?
May/June 2011
Chlorine is made by electrolysing brine, which is concentrated aqueous sodium chloride.
May/June 2011
What pattern is seen as you move down Group VII?
May/June 2012
In the two experiments described below, anhydrous potassium chloride is used and the results labelled X and Y are noted at the end of each one. Concentrated sulfuric acid is added to the potassium chloride, and the fumes given off are passed through aqueous potassium iodide solution – observation X. The potassium chloride is first dissolved in aqueous ammonia, and this solution is then mixed with aqueous silver nitrate – observation Y. What are observations X and Y?
May/June 2012
Which of the following statements are true for all three halogens, chlorine, bromine and iodine?
May/June 2012
Chlorine has oxidation states in its compounds that extend from $-1$ up to $+7$. What reagent(s) and conditions are required to oxidise elemental chlorine to a compound in which chlorine has the $+5$ oxidation state?
May/June 2012
What pattern is seen as you go down Group VII?
May/June 2012
Which of the following statements is true for all three halogens, chlorine, bromine and iodine?
May/June 2012
$Y$ is a salt of one of the halogens chlorine, bromine, iodine, or astatine (element $85$). The reaction scheme illustrates a sequence of reactions in which a solution of $Y$ is used as the starting reagent.
May/June 2013
When a red-hot platinum wire is lowered into a test tube containing hydrogen iodide, the gas breaks down into its elements. If the same experiment is carried out with hydrogen chloride, there is no reaction. Which factors help explain this behaviour?
May/June 2013
Halogen lamps are fitted to many modern cars. Right after these lamps are switched on, a noticeable purple colour can be observed. Which species is causing this purple colour?
May/June 2013
Two students, P and Q, were told to produce bar charts showing the differences in size of some properties of the halogens and their compounds. Their diagrams are shown. Which of the students’ diagrams is/are correct?
May/June 2013
Redox reactions take place very often in the chemistry of Group VII. Which statement is correct?
May/June 2014
A test tube containing HBr(g) and another test tube containing HI(g) are warmed to the same temperature. Which pairing of observations could be seen?
May/June 2014
In this question, K, L and M each stand for a halogen atom or a halide ion. For every sub-question, use the information given and finish the answer lines below.
May/June 2014
The halogens and their compounds are used in many different ways, and the chemical and physical properties of these elements display orderly patterns that are linked to their positions in Group VII.
May/June 2014
Astatine, At, is placed underneath iodine in Group VII of the Periodic Table. Which of the following statements is most likely to be correct?
May/June 2015
Astatine, $\text{At}$, is the element located below iodine in Group VII of the Periodic Table. Which of the following statements about $\text{At}$ would be expected to be correct?
May/June 2015
The solids sodium chloride and sodium iodide each react with concentrated sulfuric acid at room temperature. For NaCl, the products formed are NaHSO$_4$ and HCl. For NaI, the products formed are NaHSO$_4$, HI, I$_2$, SO$_2$, H$_2$O, S and H$_2$S. Which explanation best accounts for the difference in the products?
May/June 2016
Astatine, At, lies beneath iodine in Group 17 of the Periodic Table. Which of the following statements about At are likely to be correct?
May/June 2016
Which properties become larger in the order hydrogen chloride, hydrogen bromide and hydrogen iodide?
May/June 2016
The Group 17 elements, known as the halogens, together with their compounds, exhibit a number of similarities and patterns in their properties. Data are supplied for the elements from fluorine to iodine.
May/June 2016
Which reactions have the colour changes stated accurately?
May/June 2017
The powder is known to be either a single sodium halide or a blend of two sodium halides. A portion of the powder was dissolved in water. Aqueous silver nitrate was added, and a pale yellow precipitate appeared. When concentrated aqueous ammonia was then added, part of this precipitate dissolved, leaving behind a darker yellow precipitate. What could the powder be?
May/June 2017
The halogens, chlorine, bromine and iodine, together with their compounds, display several similarities and patterns in their physical and chemical properties.
May/June 2017
A solution of potassium iodide is treated with aqueous silver nitrate. Next, aqueous ammonia is added. What observations would be made?
May/June 2018
When concentrated sulfuric acid is added to solid sodium bromide, bromine gas is formed together with several other products. However, when concentrated sulfuric acid is added to solid sodium chloride, only hydrogen chloride and sodium hydrogensulfate are formed. What accounts for this difference?
May/June 2018
The Group 17 elements, called the halogens, exhibit patterns in both chemical and physical properties. Their elements and compounds are employed in a wide range of ways.
May/June 2018
A small amount of hot, concentrated sulfuric acid is added separately to solid samples of potassium halides, $\text{KX}$. Which of the potassium halides reacts to form a mixture of products that includes a halogen, $\text{X}_2$?
May/June 2019
Elements in Group 17 are known as the halogens.
May/June 2019
Iodine belongs to Group $17$ in the Periodic Table.
May/June 2019
Astatine, At, is positioned beneath iodine in Group $17$ of the Periodic Table. Which statement is most likely to be true?
May/June 2020
Which statement accounts for iodine being less volatile than chlorine?
May/June 2020
The equation shown in part (a)(i) represents the reaction that takes place when aqueous potassium iodide is added to aqueous copper(II) sulfate. A white precipitate of copper(I) iodide is produced in a brown solution of iodine and potassium sulfate.
May/June 2020
As you move down Group 17 from chlorine to iodine, which statement is correct?
May/June 2021
Which reagents are used to form a solution of sodium chlorate(V)?
May/June 2021
At room temperature, concentrated sulfuric acid reacts with sodium halide salts.
May/June 2021
A metal from Group 2 reacts with bromine to make the crystalline compound $\text{MBr}_2$. An excess of aqueous $\text{AgNO}_3$ is then added to a solution of $\text{MBr}_2$, causing a precipitate to appear. The mixture is filtered, the precipitate is dried, and its mass is measured.
May/June 2021
The elements in Group 17 are called the halogens.
May/June 2021
When solid sodium iodide reacts with concentrated sulfuric acid, more than one sulfur-containing product is formed. What is the smallest oxidation number of sulfur in these products?
May/June 2022
Which reaction mixture gives off an acidic gas?
May/June 2022
The physical properties of Period 3 elements and their compounds follow trends.
May/June 2022
Which row gives the predicted properties of astatine when it is compared with iodine?
May/June 2023
Which of the following statements about the halogens is correct?
May/June 2023
Chlorine is an element that reacts very readily.
May/June 2023
In the laboratory, hydrogen chloride gas is produced by adding concentrated sulfuric acid to potassium chloride. Write an equation for this reaction.
May/June 2023
Q dissolves in water. $Q(aq)$ does not show any reaction with dilute sulfuric acid. A precipitate is formed when aqueous silver nitrate is added to $Q(aq)$. This precipitate is only partly soluble in aqueous ammonia. What might compound Q be?
May/June 2024
Chlorine gas is made to react with cold aqueous sodium hydroxide. Which statement about this reaction is correct?
May/June 2024
The table gives statements about some properties of halogens and their compounds, together with explanations for those properties. Which row gives a correct statement of the property and a correct explanation for that statement?
May/June 2024
$\text{ICl}$ forms when $\text{Cl}_2$ and $\text{I}_2$ react with each other. $\text{Cl}_2 + \text{I}_2 \rightleftharpoons 2\text{ICl}$ $\text{ICl}$ then reacts in water. $5\text{ICl} + 3\text{H}_2\text{O} \rightarrow 5\text{HCl} + \text{HIO}_3 + 2\text{I}_2$ Which row is right?
May/June 2024
The elements in Group 17 are known as halogens.
May/June 2024
Which statement concerning the properties of halogens and hydrogen halides is correct?
May/June 2025
Which statement describes the halogens chlorine, bromine and iodine?
Oct/Nov 2010
Which of the following statements about bromine is correct?
Oct/Nov 2010
Concentrated sulfuric acid reacts with solid sodium chloride at room temperature, and it also reacts with solid sodium iodide at room temperature. Which row correctly describes the way concentrated sulfuric acid behaves in each reaction?
Oct/Nov 2010
Which statement gives the correct description of the halogens chlorine, bromine and iodine?
Oct/Nov 2010
Chile saltpetre, $\text{NaNO}_3$, has sodium iodide as an impurity. Aqueous silver nitrate is added to an aqueous solution of Chile saltpetre. Concentrated aqueous ammonia is then added. Which observations would be seen?
Oct/Nov 2010
The gaseous hydrogen halides $\text{HCl}$, $\text{HBr}$ and $\text{HI}$ can be made by reacting the matching sodium salt with anhydrous phosphoric(V) acid, $\text{H}_3\text{PO}_4$. When the sodium halide $\text{NaX}$ was employed, the reaction below took place and a sample of gaseous $\text{HX}$ was collected in a gas jar. $ \text{NaX} + \text{H}_3\text{PO}_4 \rightarrow \text{NaH}_2\text{PO}_4 + \text{HX} $ A hot glass rod was then inserted into the sample of $\text{HX}$ and a red/orange colour appeared at once.
Oct/Nov 2010
The element astatine, $\text{At}$, is positioned below iodine in Group VII of the Periodic Table. Which statements about $\text{At}$ are correct?
Oct/Nov 2012
Astatine, At, is positioned below iodine in Group VII of the Periodic Table. Which of the following statements about At are correct?
Oct/Nov 2012
The Group VII elements chlorine, bromine and iodine each form a hydride.
Oct/Nov 2012
The Group VII elements chlorine, bromine and iodine each form a hydride.
Oct/Nov 2012
Concentrated sulfuric acid can be used in a school or college laboratory to make hydrogen chloride by reacting it with solid chlorides such as sodium chloride.
Oct/Nov 2012
Chlorine gas is produced by electrolysing brine in a diaphragm cell.
Oct/Nov 2013
Chlorine gas is produced by carrying out electrolysis of brine in a diaphragm cell.
Oct/Nov 2013
The properties of the elements in Group VII of the Periodic Table vary from one member to the next.
Oct/Nov 2013
When heated, hydrogen iodide decomposes more rapidly than hydrogen chloride. Which of the following statements account for this higher rate?
Oct/Nov 2014
When chlorine gas is added to cold aqueous sodium hydroxide, a reaction takes place. It also reacts with hot aqueous sodium hydroxide. What oxidation numbers does chlorine have in the products of these reactions?
Oct/Nov 2014
The graph shows the successive ionisation energies of the elements from fluorine, F, to bromine, Br.
Oct/Nov 2014
Which statement about bromine is the correct one?
Oct/Nov 2015
When aqueous silver nitrate is added to aqueous barium chloride, a white precipitate is formed that dissolves in excess dilute aqueous ammonia, giving a colourless solution. If excess dilute nitric acid is then added to the colourless solution, a white precipitate, Z, is formed. What is Z?
Oct/Nov 2015
A white powder consists of sodium chloride and sodium iodide. It is dissolved in water in a test-tube, then excess aqueous silver nitrate is added. A precipitate, $X$, forms. Next, excess concentrated ammonia is added to the test-tube containing $X$. After shaking the test-tube, a precipitate, $Y$, is seen. Which statement about $X$ or $Y$ is correct?
Oct/Nov 2015
When the ozone layer in the upper atmosphere is depleted, Earth’s natural defence against harmful ultraviolet radiation is weakened. Which compound would lead to the greatest depletion of the ozone layer?
Oct/Nov 2015
Which of the following statements about bromine is correct?
Oct/Nov 2015
When aqueous silver nitrate is mixed with aqueous barium chloride, a white precipitate forms, and this dissolves in excess dilute aqueous ammonia to give a colourless solution. If excess dilute nitric acid is then added to the colourless solution, a white precipitate, Z, is formed. What is Z?
Oct/Nov 2015
A comparison is made of the properties of chlorine, bromine and their compounds. Which property is lower for chlorine than for bromine?
Oct/Nov 2016
J is a salt of one of the halogens chlorine, bromine, iodine or astatine. The reaction sequence below shows a set of reactions that uses a solution of J as the starting reagent. $\text{J(aq)} \xrightarrow[\text{AgNO}_3(aq)]{\text{HNO}_3(aq)}$ a precipitate $\xrightarrow[\text{dilute NH}_3(aq)]{\text{an excess of}}$ a colourless solution $\xrightarrow[\text{HNO}_3(aq)]{\text{an excess of}}$ a precipitate. Which salt could J be?
Oct/Nov 2016
Chlorine and bromine differ in volatility. Which row names the more volatile element, and states the correct reason?
Oct/Nov 2016
A comparison is made between the properties of chlorine, bromine and the compounds they form. Which property is lower for chlorine than for bromine?
Oct/Nov 2016