A Level Chemistry 9701 Paper 12, Oct/Nov 2025

What is the electrons in boxes notation for the ${\text{Fe}}^{3+}$ ion? A [Ar] 3d: [⥮][⥮][ ][ ][ ], 4s: [⥮] B [Ar] 3d: [⥮][⥮][⥮][ ][ ], 4s: [⥮] C [Ar] 3d: [⥮][⥮][⥮][⥮][ ], 4s: [ ] D [Ar] 3d: [⥮][⥮][⥮][⥮][⥮], 4s: [ ]

Which equation has an energy change that is equal to the first ionisation energy of bromine? A $\text{Br(g)}\to {\text{Br}}^{+}(\text{g})+{\text{e}}^{-}$ B $\text{Br(g)}\to {\text{Br}}^{-}(\text{g})-{\text{e}}^{-}$ C $\frac{1}{2}{\text{Br}}_2(\text{g})\to {\text{Br}}^{+}(\text{g})+{\text{e}}^{-}$ D $\frac{1}{2}{\text{Br}}_2(\text{g})\to {\text{Br}}^{-}(\text{g})-{\text{e}}^{-}$

The reaction of hydrogen sulfide with sulfur dioxide gives sulfur as one of the products. The two relevant redox equations are shown. $${\text{H}}_2\text{S(aq)}\rightleftharpoons \text{S(s)}+2{\text{H}}^{+}(\text{aq})+2{\text{e}}^{-}$$ $${\text{SO}}_2(\text{aq})+4{\text{H}}^{+}(\text{aq})+4{\text{e}}^{-}\rightleftharpoons \text{S(s)}+2{\text{H}}_2\text{O(l)}$$ How many moles of hydrogen sulfide are needed to react with sulfur dioxide to produce $1\text{ mol}$ of sulfur? A $\frac{1}{3}\text{ mol}$ B $\frac{2}{3}\text{ mol}$ C $\frac{3}{2}\text{ mol}$ D $2\text{ mol}$

Which statement is correct? A The relative atomic mass of a ${}^{35}\text{Cl}$ atom is $35.5$. B The relative molecular mass of ${\text{O}}_2$ is $16.0$. C The relative formula mass of ${\text{CaCO}}_3$ is $100.1$. D The relative isotopic mass of a ${}^{24}\text{Mg}$ atom is $24.3$.

The bonding between two atoms of nitrogen in an ${\text{N}}_2$ molecule involves the hybridisation of atomic orbitals to form $\text{sp}$ orbitals. Which row is correct?

Three bond angles are labelled on the molecule shown. What is the order of decreasing size of the bond angles $x$, $y$ and $z$?

$\text{X}$ and $\text{Y}$ are different elements in Period 3. Atoms of $\text{X}$ and $\text{Y}$ each have only one completely filled orbital in their highest occupied energy sub-shell. $\text{Y}$ has a greater first ionisation energy than $\text{X}$. Which row shows the structure and bonding in $\text{X}$ and $\text{Y}$?

A pure sample of a gas has a density of $2.62{\text{ g dm}}^{-3}$ at $101000\text{ Pa}$ and $25{}^{\circ }\text{C}$. The gas behaves ideally under these conditions. Which expression gives the $M_r$ of the gas? A $\frac{101000\times 0.001}{2.62\times 8.31\times 25}$ B $\frac{101000\times 0.001}{2.62\times 8.31\times 298}$ C $\frac{2.62\times 8.31\times 25}{101000\times 0.001}$ D $\frac{2.62\times 8.31\times 298}{101000\times 0.001}$

When $0.47\text{ g}$ of a hydrocarbon is completely burnt in air, the energy released heats $200\text{ g}$ of water from $23.7{}^{\circ }\text{C}$ to $41.0{}^{\circ }\text{C}$. What is the amount of energy absorbed, in Joules, by the water? A $0.47\times 4.18\times 17.3$ B $0.47\times 4.18\times (273+17.3)$ C $200\times 4.18\times 17.3$ D $200\times 4.18\times (273+17.3)$

One commercially available 'heat pad' contains iron, activated carbon and water. The 'heat pad' is activated by air. This causes the pad to get hotter. Which statement describes the chemical reaction occurring in the 'heat pad' when it is exposed to air? A The reaction is endothermic and iron gains electrons. B The reaction is endothermic and iron loses electrons. C The reaction is exothermic and iron gains electrons. D The reaction is exothermic and iron loses electrons.

In which substance is the average oxidation number of sulfur the highest? A ${\text{S}}_8$ B ${\text{Na}}_2{\text{S}}_4{\text{O}}_6$ C ${\text{Na}}_2{\text{S}}_2{\text{O}}_3$ D ${\text{SO}}_2{\text{Cl}}_2$

An equilibrium can be represented by the equation shown. $$\text{P(aq)}+\text{Q(aq)}\rightleftharpoons 2\text{R(aq)}+\text{S(aq)}$$ In a certain mixture, of volume $1.0{\text{ dm}}^3$, the equilibrium concentration of $\text{Q}$ is $10{\text{ mol dm}}^{-3}$. What will be the new equilibrium concentration of $\text{Q}$ if $5.0\text{ mol}$ of pure $\text{Q}$ is completely dissolved in the mixture? A $15{\text{ mol dm}}^{-3}$ B between $10{\text{ mol dm}}^{-3}$ and $15{\text{ mol dm}}^{-3}$ C $10{\text{ mol dm}}^{-3}$ D between $5.0{\text{ mol dm}}^{-3}$ and $10{\text{ mol dm}}^{-3}$

In the Contact process, sulfur dioxide and oxygen react to form sulfur trioxide. In the Haber process, nitrogen and hydrogen react to form ammonia. Which statement about these processes is correct? A $K_p$ for the Haber process has no unit. B In the Contact process, the value of $K_p$ falls when pressure is increased at constant $T$. C The Haber process uses a homogeneous catalyst. D When ${\text{V}}_2{\text{O}}_5$ is used in the Contact process, the position of equilibrium is unchanged.

$20.0{\text{ cm}}^3$ of hydrogen peroxide decomposes to water and oxygen in the presence of a suitable catalyst. $160{\text{ cm}}^3$ of oxygen, measured at room conditions, is produced in $5.00\text{ minutes}$. What is the average rate of decomposition of hydrogen peroxide during this reaction period? A $2.22\times {10}^{-5}{\text{ mol s}}^{-1}$ B $4.44\times {10}^{-5}{\text{ mol s}}^{-1}$ C $1.76\times {10}^{-4}{\text{ mol s}}^{-1}$ D $2.67\times {10}^{-3}{\text{ mol s}}^{-1}$

Which reaction pathway diagram shows an endothermic reaction that occurs in two steps and in which the second step of the reaction is likely to be faster than the first? A Reaction pathway with energy of products higher than reactants, first peak lower than second peak B Reaction pathway with energy of products lower than reactants, first peak lower than second peak C Reaction pathway with energy of products higher than reactants, first peak higher than second peak D Reaction pathway with energy of products lower than reactants, first peak higher than second peak

Oxides of nitrogen, ${\text{NO}}_x$, are involved in formation of photochemical smog and acid rain. Which oxides of nitrogen are involved in each of these processes?

Sodium and sulfur react together to form sodium sulfide, ${\text{Na}}_2\text{S}$. How do the atomic radius and ionic radius of sodium compare with those of sulfur?

Compound $\text{X}$ is an oxide of a Period 3 element. Compound $\text{X}$ is a white solid at $25{}^{\circ }\text{C}$. It reacts with water to form an acidic solution. What is compound $\text{X}$? A aluminium oxide B silicon dioxide C sulfur dioxide D phosphorus(V) oxide

When heated, magnesium nitrate decomposes. Which equation for the thermal decomposition of magnesium nitrate is correct? A ${\text{Mg(NO}}_3{)}_2\to \text{MgO}+{\text{NO}}_2+\text{NO}+{\text{O}}_2$ B $2{\text{Mg(NO}}_3{)}_2\to 2\text{MgO}+4\text{NO}+3{\text{O}}_2$ C $2{\text{Mg(NO}}_3{)}_2\to 2\text{MgO}+4{\text{NO}}_2+{\text{O}}_2$ D $3{\text{Mg(NO}}_3{)}_2\to {\text{Mg}}_2{\text{N}}_3+\text{MgO}+3\text{NO}+7{\text{O}}_2$

$\text{R}$ is the aqueous solution of an ionic compound. ● A white precipitate is formed when $\text{R}$ is added to ${\text{Sr(NO}}_3{)}_2(\text{aq})$. ● No visible reaction is seen when $\text{R}$ is added to dilute ${\text{HNO}}_3(\text{aq})$. What is the anion present in compound $\text{R}$? A ${\text{Cl}}^{-}$ B ${\text{SO}}_4^{2-}$ C ${\text{HCO}}_3^{-}$ D ${\text{CO}}_3^{2-}$

In an experiment, $0.600\text{ mol}$ of chlorine gas, ${\text{Cl}}_2$, is reacted with an excess of hot aqueous sodium hydroxide. One of the products is ${\text{NaClO}}_3$. Which mass of ${\text{NaClO}}_3$ is formed? A $21.3\text{ g}$ B $44.7\text{ g}$ C $63.9\text{ g}$ D $128\text{ g}$

$\text{X}$ and $\text{Y}$ are sodium salts of Group 17 elements. When $\text{X}$ reacts with concentrated sulfuric acid, hydrogen sulfide, ${\text{H}}_2\text{S}$, is produced. When $\text{Y}$ reacts with concentrated sulfuric acid, there is no change in the oxidation number of the sulfur. Which statement is correct? A Aqueous $\text{X}$ reduces aqueous bromine. B Aqueous $\text{Y}$ reacts with aqueous silver nitrate to give a precipitate which is insoluble in concentrated aqueous ammonia. C $\text{X}$ and $\text{Y}$ react separately with concentrated sulfuric acid to produce halogens. D When $\text{X}$ reacts with concentrated sulfuric acid, six halide ions are needed to reduce one sulfur atom to ${\text{H}}_2\text{S}$.

Element $\text{E}$ is in Period 3. It forms a chloride which reacts with a small amount of water to produce a white precipitate and steamy fumes. This precipitate is soluble in $\text{NaOH(aq)}$ and in $\text{HCl(aq)}$. What is element $\text{E}$? A magnesium B aluminium C silicon D phosphorus

Four reaction mixtures are listed. 1 $({\text{NH}}_4{)}_2{\text{SO}}_4(\text{aq})$ and $\text{NaOH}$ 2 ${\text{NH}}_4\text{Cl(aq)}$ and ${\text{Ba(OH)}}_2$ 3 ${\text{NH}}_4\text{Cl(aq)}$ and ${\text{Na}}_2\text{O}$ 4 $({\text{NH}}_4{)}_3{\text{PO}}_4(\text{aq})$ and $\text{HCl}$ Which reaction mixtures produce ammonia as a product? A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 and 4 only

Two statements about a molecule of methanal are given. 1 It is planar. 2 It contains three $\sigma$ bonds. Which statements are correct? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

The structure of disodium cromoglycate is shown. How many chiral centres are there in this molecule? A 0 B 1 C 2 D 3

What is the major product when 2-methylpent-2-ene reacts with hydrogen bromide? A 1-bromo-2-methylpentane B 2-bromo-2-methylpentane C 3-bromo-2-methylpentane D 4-bromo-2-methylpentane

Pent-2-ene is reacted with cold, dilute, acidified manganate(VII) ions. What is the major product? A ${\text{CH}}_3{\text{CH}}_2{\text{CH(OH)CH(OH)CH}}_3$ B ${\text{CH}}_3{\text{CH}}_2{\text{COCOCH}}_3$ C a mixture of ${\text{CH}}_3{\text{CH}}_2{\text{CH(OH)CH}}_2{\text{CH}}_3$ and ${\text{CH}}_3{\text{CH}}_2{\text{CH}}_2{\text{CH(OH)CH}}_3$ D ${\text{CH}}_3{\text{CH}}_2\text{COOH}$ and ${\text{CH}}_3\text{COOH}$

Limonene is an oil formed in the peel of citrus fruits. Which product is formed when an excess of bromine, ${\text{Br}}_2(\text{l})$, reacts with limonene at room temperature in the dark? A Product with addition of Br across ring double bond B Product with addition of two Br atoms across ring double bond C Product with addition of two Br atoms across side-chain double bond D Product with addition of four Br atoms across both double bonds

Which reaction mixture produces a nitrile? A halogenoalkane with $\text{KCN}$ in ethanol B halogenoalkane with ${\text{NH}}_3$ in ethanol C ketone with 2,4-DNPH D carboxylic acid with ${\text{NH}}_3$ in water

Which reaction is classified as ${\text{S}}_{\text{N}}1$? A the reaction of 1-chloropropane with ammonia in ethanol B the reaction of 1-chloropropane with potassium hydroxide in ethanol C the reaction of 2-chloro-2-methylpropane with potassium cyanide in ethanol D the reaction of 2-chloro-2-methylpropane with potassium hydroxide in ethanol

Which reaction mixture produces a primary alcohol as the major product? A propanone with ${\text{NaBH}}_4$ B propene with steam in the presence of ${\text{H}}_3{\text{PO}}_4$ C butanoic acid with ${\text{LiAlH}}_4$ D ethene with hot concentrated acidified ${\text{KMnO}}_4$

${\text{HOCH}}_2\text{CHO}$ is heated under reflux with an excess of acidified ${\text{K}}_2{\text{Cr}}_2{\text{O}}_7$ until there is no further reaction. What is the final product of this reaction? A $\text{HOOCCHO}$ B ${\text{HOCH}}_2\text{COOH}$ C $\text{HOOCCOOH}$ D ${\text{HOOCCH}}_2\text{COOH}$

An organometallic lithium compound, $\text{RLi}$, contains the nucleophile ${\text{R}}^{-}$. ${\text{CH}}_3{\text{CH}}_2\text{Li}$ reacts with pentan-2-one. The mechanism is nucleophilic addition. The first step produces an anion which is then protonated to form the final product. Which organic product is formed? A heptan-2-ol B 3-methylhexan-3-ol C 3-ethylpentan-3-ol D nonan-4-ol

The structure of a naturally occurring compound, Q, is shown. Compound Q is heated under reflux with an excess of acidified ${\text{KMnO}}_4$. Organic product R is formed. Which row is correct?

Which organic starting material could be used in a single reaction to produce propanoic acid? A ethanenitrile B propan-2-ol C propanal D propyl ethanoate

In four separate reactions, W, X, Y and Z, $1\text{ mol}$ of an organic compound reacts with an excess of a reagent.

The volume of any gas produced is collected and measured. All gas volumes are measured at the same temperature and pressure. What is the order of the reactions from greatest total volume of gas collected to least total volume of gas collected?

Butylamine can be produced by the reaction of butanenitrile with hydrogen in the presence of a suitable catalyst. Which volume of hydrogen, measured at room conditions, is required to react completely with $0.500\text{ g}$ of butanenitrile? A $145{\text{ cm}}^3$ B $174{\text{ cm}}^3$ C $289{\text{ cm}}^3$ D $348{\text{ cm}}^3$

A section of an addition polymer is shown. Which monomer is used to make this polymer? A ${\text{CH}}_2=\text{CH}-\text{O}-\text{CO}-{\text{CH}}_3$ B ${\text{CH}}_2=\text{CH}-\text{CO}-\text{O}-{\text{CH}}_3$ C ${\text{CH}}_3-\text{CH}=\text{CH}-\text{O}-\text{CO}-{\text{CH}}_3$ D ${\text{CH}}_2=\text{C}({\text{OCOCH}}_3{)}_2$

The purity of a compound can be determined using infrared spectroscopy. The table gives the characteristic infrared absorption frequencies for some selected bonds.

Propan-2-ol is made by hydration of propene. A sample of the product is obtained. Which feature of the infrared spectrum of the product would show that no propene remains in the product? A absorption in the $2900{\text{ cm}}^{-1}$ region B strong absorption below $1000{\text{ cm}}^{-1}$ C the lack of absorption at or near $1250{\text{ cm}}^{-1}$ D the lack of absorption at or near $1550{\text{ cm}}^{-1}$