A Level Chemistry 9701 Paper 13, May/June 2026

What is the electronic configuration of ${\text{Cr}}^{3+}$? A $[\text{Ar}]3{\text{d}}^{1}4{\text{s}}^2$ B $[\text{Ar}]3{\text{d}}^{2}4{\text{s}}^2$ C $[\text{Ar}]3{\text{d}}^{3}4{\text{s}}^0$ D $[\text{Ar}]3{\text{d}}^{4}4{\text{s}}^0$

Which molecule has the greatest bond angle? A ${\text{SCl}}_2$ B ${\text{BCl}}_3$ C ${\text{PCl}}_3$ D ${\text{CCl}}_4$

Antimony is produced in a 2-stage process from its sulfide, ${\text{Sb}}_2{\text{S}}_3$. • ${\text{Sb}}_2{\text{S}}_3$ is heated in oxygen, producing ${\text{Sb}}_2{\text{O}}_3$ and ${\text{SO}}_2$. • The ${\text{Sb}}_2{\text{O}}_3$ is then reduced by carbon, producing $\text{Sb}$ and ${\text{CO}}_2$. What is the maximum volume of ${\text{CO}}_2$, measured at room conditions, produced from $20\text{ mol}$ of ${\text{Sb}}_2{\text{S}}_3$? A $30{\text{ dm}}^3$ B $360{\text{ dm}}^3$ C $720{\text{ dm}}^3$ D $1440{\text{ dm}}^3$

The ${}^{68}\text{Ge}$ isotope undergoes a natural radioactive process to give an isotope of a different element, ${}^{68}\text{X}$. This transformation of ${}^{68}\text{Ge}$ occurs when an electron enters the nucleus and changes a proton into a neutron. Which statement about the composition of an atom of ${}^{68}\text{X}$ is correct? A It has 37 neutrons. B It has 13 electrons in its 4th shell. C It has 4 electrons in its 4p orbital. D Its proton number is 32.

Oxygen reacts with ammonia to form nitrogen(II) oxide, $\text{NO}$, and steam. How many moles of oxygen are required to convert $10.0\text{ mol}$ of ammonia into nitrogen(II) oxide and steam? A 5.0 B 12.5 C 15.0 D 25.0

Some orbital overlaps that occur in molecules are listed. 1 a p orbital with a p orbital 2 a p orbital with an sp hybrid orbital 3 an s orbital with an sp hybrid orbital 4 an sp hybrid orbital with an sp hybrid orbital Which orbital overlaps occur in the ethyne molecule, $\text{H–C}\equiv \text{C–H}$? A 1, 2, 3 and 4 B 1, 3 and 4 only C 1 and 4 only D 2, 3 and 4 only

In the ideal gas equation $pV=nRT$, what do the symbols $n$ and $T$ represent?

Bond energy data can be used to calculate the enthalpy change of a reaction. Bromoethane, ${\text{CH}}_3{\text{CH}}_2\text{Br}$, can be made by reacting ethene with hydrogen bromide. $${\text{CH}}_2={\text{CH}}_2+\text{HBr}\to {\text{CH}}_3{\text{CH}}_2\text{Br}$$

What is the enthalpy change for this reaction? A $-346{\text{ kJ mol}}^{-1}$ B $-64{\text{ kJ mol}}^{-1}$ C $+64{\text{ kJ mol}}^{-1}$ D $+346{\text{ kJ mol}}^{-1}$

Sulfur can be oxidised in two ways. $$\text{S(s)}+{\text{O}}_2\text{(g)}\to {\text{SO}}_2\text{(g)}\mathrm{\Delta }{H}^{\circ }=-296.5{\text{ kJ mol}}^{-1}$$ $$2\text{S(s)}+3{\text{O}}_2\text{(g)}\to 2{\text{SO}}_3\text{(g)}\mathrm{\Delta }{H}^{\circ }=-791.4{\text{ kJ mol}}^{-1}$$ Sulfur trioxide can be made from sulfur dioxide and oxygen. $$2{\text{SO}}_2\text{(g)}+{\text{O}}_2\text{(g)}\to 2{\text{SO}}_3\text{(g)}$$ What is the standard enthalpy change for this reaction? A $-1384.4{\text{ kJ mol}}^{-1}$ B $-989.8{\text{ kJ mol}}^{-1}$ C $-494.9{\text{ kJ mol}}^{-1}$ D $-198.4{\text{ kJ mol}}^{-1}$

Aqueous sodium chlorate(I) is added to aqueous iron(II) sulfate and a reaction takes place. Aqueous sodium chlorate(I) behaves as an oxidising agent in this reaction. Which statement about the reaction is correct? A Iron(II) ions gain electrons to become iron atoms. B Iron(II) ions gain electrons to become iron(III) ions. C Iron(II) ions lose electrons to become iron atoms. D Iron(II) ions lose electrons to become iron(III) ions.

Which conversion involves the oxidation of an element in the reactant shown? A ${\text{CO}}_2\to {\text{CO}}_3^{2-}$ B ${\text{FeCl}}_3\to {\text{FeCl}}_2$ C ${\text{NH}}_4^{+}\to {\text{NH}}_3$ D ${\text{SO}}_2\to {\text{SF}}_6$

Solid ammonium chloride is heated to a certain temperature in a $0.500{\text{ dm}}^3$ container. Ammonia and hydrogen chloride are formed. $${\text{NH}}_4\text{Cl(s)}\rightleftharpoons {\text{NH}}_3\text{(g)}+\text{HCl(g)}$$ When the initial amount of ammonium chloride is $1.00\text{ mol}$ there is $0.300\text{ mol}$ of ammonium chloride present at equilibrium. What is the numerical value of $K_c$ for this reaction under these conditions? A 0.490 B 1.63 C 1.96 D 3.27

When ethanoic acid is mixed with ethanol a reversible reaction occurs. Which statement describes this reaction when it reaches dynamic equilibrium? A The concentrations of the reactants and products are constant. B This dynamic equilibrium can only be reached by the forward reaction. C The rates of the forward and backward reactions are not equal. D The forward and backward reactions have stopped.

The reaction pathway diagram shows the reaction which occurs when $({\text{CH}}_3{)}_3\text{CCl}$ reacts with ${\text{OH}}^{-}$. Which statements are correct?

The graph shows a Boltzmann distribution for a sample of reacting gas at a temperature $T\text{ K}$. The activation energy, $E_{\text{A}}$, for the reaction is marked. Point Q is the point of intercept of the curve with the value of the activation energy, $E_{\text{A}}$. Two changes are made. 1 The temperature is increased to $(T+10)\text{ K}$. 2 A catalyst is added which increases the rate of the reaction. As a result of the change in temperature, the shape of the distribution curve will change. Which point shows the intercept of the new distribution curve with the value of the activation energy for the catalysed reaction?

Elements W, X, Y and Z are different elements in Period 3 of the Periodic Table. Four statements about W, X, Y and Z are given. 1 X has the greatest electronegativity value of the four elements. 2 W reacts with X to produce a liquid at room temperature that reacts with water to form an acidic solution. 3 Z reacts with water to form an alkaline solution. 4 The oxide of Y will react with the solutions formed in statements 2 and 3. What is the correct order of these elements in order of increasing atomic radius? A $\text{X}\to \text{Y}\to \text{W}\to \text{Z}$ B $\text{X}\to \text{W}\to \text{Y}\to \text{Z}$ C $\text{Z}\to \text{Y}\to \text{W}\to \text{X}$ D $\text{Z}\to \text{Y}\to \text{X}\to \text{W}$

The table shows the melting points of ${\text{SiO}}_2$ and ${\text{P}}_4{\text{O}}_6$.

Which statement explains the difference between the melting points of ${\text{SiO}}_2$ and ${\text{P}}_4{\text{O}}_6$? A The bonding of the oxides changes from ionic to covalent. B The metallic character of the elements decreases across Period 3. C The oxidation number of the elements increases from Si to P. D The structure changes from giant molecular to simple molecular.

Which statement explains the relative reactivities of calcium and strontium with hydrochloric acid? A Calcium is more reactive because it contains fewer protons in its nucleus. B Calcium is more reactive because it has a smaller atomic radius. C Calcium is less reactive because it contains fewer protons in its nucleus. D Calcium is less reactive because it has a smaller atomic radius.

When hydrated magnesium nitrate, ${\text{Mg(NO}}_3{)}_2\cdot 7{\text{H}}_2\text{O}$, is heated, which three gases are given off? A nitrogen(II) oxide, oxygen and water vapour B hydrogen, nitrogen and oxygen C hydrogen, nitrogen(IV) oxide and oxygen D nitrogen(IV) oxide, oxygen and water vapour

Trends are seen in the physical and chemical properties of the elements of Group 2 and their compounds. Which property shows an increase from magnesium to barium? A the electronegativity of the elements B the solubility of the hydroxides C the solubility of the sulfates D the first ionisation energy of the elements

Chlorine gas reacts with hot dilute aqueous sodium hydroxide as shown. $$u{\text{Cl}}_2+v{\text{OH}}^{-}\to w{\text{Cl}}^{-}+y{\text{ClO}}_3^{-}+z{\text{H}}_2\text{O}$$ What is the simplest ratio of $w:y$ in the balanced equation? A 1 : 1 B 1 : 5 C 5 : 1 D 7 : 1

Concentrated sulfuric acid is added to $\text{KX(s)}$, where X is Br, Cl or I. The element sulfur and the halogen molecule, ${\text{X}}_2$, are two of the products made in this reaction. What is the colour of ${\text{X}}_2$ in the gaseous state? A brown B colourless C purple D yellow-green

Which statement about the reactions of nitrogen oxides in the atmosphere is correct? A $\text{NO}$ oxidises ${\text{SO}}_2$. B $\text{NO}$ reduces ${\text{SO}}_2$. C ${\text{NO}}_2$ reduces ${\text{SO}}_2$. D ${\text{NO}}_2$ oxidises ${\text{SO}}_2$.

Ammonium sulfate is heated with calcium hydroxide. Two statements about the reaction are listed. 1 The ammonium ion acts as a base during the reaction. 2 The $\text{H–N–H}$ bond angle decreases during the reaction. Which statements are correct? A both statement 1 and statement 2 B statement 1 only C statement 2 only D neither statement 1 nor statement 2

The skeletal structure of hexamine is shown. What is the empirical formula of hexamine? A ${\text{CH}}_2\text{N}$ B ${\text{C}}_3{\text{H}}_6{\text{N}}_2$ C ${\text{C}}_4{\text{H}}_8{\text{N}}_4$ D ${\text{C}}_6{\text{H}}_{12}{\text{N}}_4$

A student looks at the structure of chloroethene and of poly(chloroethene) and draws two conclusions. 1 The carbon atoms are ${\text{sp}}^3$ hybridised in each substance. 2 Chloroethene and poly(chloroethene) contain chiral carbon atoms. Which conclusions are true or false?

Alkenes react with hydrogen bromide. The reaction proceeds via an intermediate carbocation. The more stable the intermediate, the faster the reaction. Which sequence correctly shows an increase in the rate of reaction of the alkenes with hydrogen bromide? A ethene $\to$ propene $\to$ 2-methylpropene B 2-methylpropene $\to$ propene $\to$ ethene C ethene $\to$ 2-methylpropene $\to$ propene D propene $\to$ 2-methylpropene $\to$ ethene

Ethane reacts with bromine by a free-radical substitution mechanism. The mechanism for this reaction has three steps: initiation, propagation and termination. Which species is a possible product in one of the steps? A ${\text{C}}_3{\text{H}}_8$ B ${\text{C}}_4{\text{H}}_{10}$ C ${\text{H}}^{\bullet }$ D ${\text{CH}}_4$

Structural isomerism and stereoisomerism should be taken into account when answering this question. Two compounds, X and Y, both have the molecular formula ${\text{C}}_5{\text{H}}_{11}\text{Br}$. On heating with ethanolic $\text{NaOH}$, X produces three isomeric organic products and Y produces two isomeric organic products. What could X and Y be?

Which halogenoalkane tends to react with water by an ${\text{S}}_{\text{N}}1$ mechanism and produces a yellow precipitate when ${\text{AgNO}}_3\text{(aq)}$ is added to it? A 1-chlorobutane B 1-iodobutane C 2-chloro-2-methylpropane D 2-iodo-2-methylpropane

Compound Q with molecular formula ${\text{C}}_4{\text{H}}_{10}\text{O}$ gives compound R with molecular formula ${\text{C}}_4{\text{H}}_8\text{O}$ upon oxidation. R gives a yellow precipitate with alkaline ${\text{I}}_2\text{(aq)}$. What is Q? A ${\text{CH}}_3{\text{CH}}_2{\text{CH(OH)CH}}_3$ B $({\text{CH}}_3{)}_2{\text{CHCH}}_2\text{OH}$ C ${\text{CH}}_3{\text{CH}}_2{\text{CH}}_2{\text{CH}}_2\text{OH}$ D $({\text{CH}}_3{)}_3\text{COH}$

Propanoic acid is used to make propene in two steps. What are the reagents for step 1 and step 2?

Two reactions are described. 1 1-bromopropane with ammonia 2 propanal with hydrogen cyanide Which of these reactions has a nucleophilic mechanism? A both reactions B only reaction 1 C only reaction 2 D neither reaction

The structures of compound S and compound T are shown. $${\text{HOCH}}_2\text{CH(OH)CHO}{\text{HOCH}}_2{\text{COCH}}_2\text{OH}$$ $$\text{S}\text{T}$$ Which reagent can be used to distinguish between compound S and compound T? A ${\text{Br}}_2\text{(aq)}$ B hot acidified ${\text{KMnO}}_4$ C Tollens’ reagent D warm acidified ${\text{K}}_2{\text{Cr}}_2{\text{O}}_7$

Compound Y has the molecular formula ${\text{C}}_4{\text{H}}_6{\text{O}}_2$ and reacts with $\text{Na}$ but not with ${\text{Na}}_2{\text{CO}}_3$. On warming Y with Fehling’s reagent, followed by acidification, the organic product reacts with both $\text{Na}$ and ${\text{Na}}_2{\text{CO}}_3$. What could be the structural formula of Y? A ${\text{CH}}_3{\text{CH=CHCO}}_2\text{H}$ B ${\text{OCHCH}}_2{\text{CH}}_2\text{CHO}$ C ${\text{OCHCH=CHCH}}_2\text{OH}$ D ${\text{CH}}_2={\text{CHCOCH}}_2\text{OH}$

Which pair of substances could react to give the ester ${\text{CH}}_3{\text{CH}}_2{\text{CO}}_2{\text{CH}}_3$? A ethanol and ethanoic acid B methanol and ethanoic acid C methanol and propanoic acid D propan-1-ol and methanoic acid

2-methyl-1-bromopropane is reacted with a reagent under certain conditions to form primary amine Z. The reaction produces $4.50\text{ g}$ of Z with a $56.0\mathrm{\%}$ yield. [$A_{\text{r}}$: C, 12.0; H, 1.0; Br, 79.9; N, 14.0] Which row is correct?

The structure of part of an addition polymer chain is shown. Which row gives the monomer used and the number of repeat units in the structure shown?

The infrared spectrum of compound X is shown.

What is compound X? A butane B butanal C butan-1-ol D butanoic acid

The mass spectra of pentane and methylbutane are compared. Which statement is correct? A The methylbutane spectrum has an M+1 peak but the pentane spectrum does not. B The molecular ion peak has a higher $m\mathrm{/}e$ value on the pentane spectrum. C Both spectra have a peak at $m\mathrm{/}e43$. D The pentane spectrum has a peak at $m\mathrm{/}e29$ but the methylbutane spectrum does not.