Questions 1
Topic -1.1 Particles in the atom and atomic radius
Element X has six more protons than element Y. Which statement must be correct?
A Atoms of element Y are smaller than atoms of element X.
B Element X has a full shell of electrons.
C Element X and element Y are in the same group.
D Element X and element Y are in the same period.
▶️Answer/Explanation
Ans: B
Questions 2
Topic -1.1 Particles in the atom and atomic radius
Which statement explains why calcium has a higher melting point than barium?
A Calcium cations are smaller than barium cations and have a stronger attraction to the delocalised electrons.
B The structure of calcium is partly giant molecular.
C There are more delocalised electrons in calcium than in barium as it has a lower ionisation energy.
D There is greater repulsion between barium atoms as they have more complete electron
shells than calcium atoms.
▶️Answer/Explanation
Ans: A
Questions 3
Topic -1.4 Ionisation energy
Three statements about potassium and chlorine and their ions are listed.
1 The atomic radius of a potassium atom is greater than the atomic radius of a chlorine atom.
2 The first ionisation energy of potassium is greater than the first ionisation energy of chlorine.
3 The ionic radius of a potassium ion is greater than the ionic radius of a chloride ion.
Which statements are correct?
A 1 only
B 2 only
C 1 and 3
D 2 and 3
▶️Answer/Explanation
Ans: A
Questions 4
Topic -7.1 Chemical equilibria: reversible reactions, dynamic equilibrium
For which equilibrium do both of the equilibrium constants \(K_c\) and \(K_p\) have no units?
A \(H_2(g) + I_2(g) \rightleftharpoons 2HI(g)\)
B \(N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3 (g)\)
C \(N_2O_4(g) \rightleftharpoons 2NO_2 (g)\)
D \(SO_2(g) + \frac{1}{2}O_2(g) \rightleftharpoons SO_3 (g)\)
▶️Answer/Explanation
Ans: A
Questions 5
Topic -5.1 Enthalpy change, ΔH
Calcium carbide, CaC₂, reacts with water, as shown. The data below the equation show, in kJ mol⁻¹, the standard enthalpies of formation of the compounds involved.
What is the standard enthalpy change of the reaction shown?
A –753 kJ mol⁻¹
B –61 kJ mol⁻¹
C +61 kJ mol⁻¹
D +753 kJ mol⁻¹
▶️Answer/Explanation
Ans: B
Questions 6
Topic -4.2 Bonding and structure
In the sodium chloride lattice the number of chloride ions that surround each sodium ion is called the coordination number of the sodium ions. What are the coordination numbers of the sodium ions and the chloride ions in the sodium chloride lattice?
▶️Answer/Explanation
Ans: C
Questions 7
Topic -3.5 Shapes of molecules
Histidine is an amino acid.
What are the approximate bond angles 1, 2, and 3? 
▶️Answer/Explanation
Ans: B
Questions 8
Topic -7.1 Chemical equilibria: reversible reactions, dynamic equilibrium
The Contact process takes place at a pressure between 100 000 Pa and 200 000 Pa. A catalyst is used. Which statement is correct?
A \(V_2O_5\) A catalyst is added to increase the equilibrium yield of the reaction.
B Changes in pressure have no effect on the position of equilibrium.
C The equilibrium yield of the reaction is very high under the conditions used.
D An iron catalyst is added to increase the rate of reaction.
▶️Answer/Explanation
Ans: C
Questions 9
Topic -6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
Bromine reacts with aqueous sodium hydroxide at 25 °C.
reaction 1 \(Br_2(aq) + 2NaOH(aq) → NaBr(aq) + NaOBr(aq) + H_2O(l)\)
The NaOBr formed is unstable at 25 °C and reacts further.
reaction 2 \(3NaOBr(aq) → 2NaBr(aq) + NaBrO_3(aq)\)
Which reactions are disproportionations?
A both reaction 1 and reaction 2
B neither reaction 1 nor reaction 2
C reaction 1 only
D reaction 2 only
▶️Answer/Explanation
Ans: A
Questions 10
Topic -2.1 Relative masses of atoms and molecules
Which statement is correct?
A The relative atomic mass of a \(^{35} Cl\) atom is 35.5.
B The relative formula mass of CaCO₃ is 100.1.
C The relative isotopic mass of a \(^{24} Mg\) atom is 24.3.
D The relative molecular mass of O₂ is 16.0.
▶️Answer/Explanation
Ans: B
Questions 11
Topic -8.1 Rate of reaction
Iodine and propanone react according to the following equation.
I₂(aq) + CH₃COCH₃(aq) → CH₃COCH₂I(aq) + HI(aq)
If the concentration of propanone is increased, keeping the total reaction volume constant, the initial rate of the reaction also increases. What could be the reason for this?
A A greater proportion of collisions are successful at the higher concentration.
B The particles are further apart at the higher concentration.
C The particles have more energy at the higher concentration.
D There are more collisions per second between particles at the higher concentration.
▶️Answer/Explanation
Ans: D
Questions 12
Topic -1.4 Ionisation energy
Four successive ionisation energies (IE) of element E are shown. Element E is in Period 3 of the Periodic Table.
In which group of the Periodic Table is E?
A 14
B 15
C 16
D 17
▶️Answer/Explanation
Ans: A
Questions 13
Topic -2.4 Reacting masses and volumes (of solutions and gases)
In this question you should assume that the gas formed behaves as an ideal gas. A 1.7 g sample of Mg reacts with 50.0 cm³ of 2.2 mol dm⁻³ HCl at 303 K and 110 400 Pa. Which volume of gas is produced, measured under these conditions?
A 1.3 \(dm^3\)
B 1.6 \(dm^3\)
C 2.5\(dm^3\)
D 5.0\(dm^3\)
▶️Answer/Explanation
Ans: A
Questions 14
Topic -2.2 The mole and the Avogadro constant
Chlorine dioxide, \(ClO_2\), reacts with aqueous sodium hydroxide to produce water and a mixture of two sodium salts, \(NaClO_2\) and \(NaClO_3\). What is the mole ratio of \(NaClO_2\) to \(NaClO_3\) in the product mixture?
A 1:2
B 3:5
C 1:1
D 5:3
▶️Answer/Explanation
Ans: C
Questions 15
Topic -3.4 Covalent bonding and coordinate (dative covalent) bonding
The temperature of a sample of an inert gas is increased. What effect does this have on the number of molecules with the most probable energy and on the number of molecules with higher energy?
▶️Answer/Explanation
Ans: B
Questions 16
Topic -2.1 Relative masses of atoms and molecules
For which compound is there the greatest percentage loss of mass on strong heating?
A anhydrous calcium carbonate
B anhydrous calcium nitrate
C anhydrous magnesium carbonate
D anhydrous magnesium nitrate
▶️Answer/Explanation
Ans: D
Questions 17
Topic -2.4 Reacting masses and volumes (of solutions and gases)
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 the 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.
▶️Answer/Explanation
Ans: C
Questions 18
Topic -3.6 Intermolecular forces, electronegativity and bond properties
SiO₂ has a melting point of 1713°C. It reacts with hot NaOH(aq) to form sodium silicate, \(Na_2SiO_3\), and water. No reaction occurs when SiO₂ is added to hot H₂SO₄(aq). What can be deduced from this information?
▶️Answer/Explanation
Ans: C
Questions 19
Topic -9.1 Periodicity of physical properties of the elements in Period 3
Element X has the second largest atomic radius in its period. An atom of X has three occupied electron shells only. The oxide of X is shaken with water. What could be the pH of the resulting solution?
A 5
B 7
C 9
D 14
▶️Answer/Explanation
Ans: C
Questions 20
Topic -5.1 Enthalpy change, ΔH
Which emission from an internal combustion engine contributes to the erosion of marble statues?
A carbon monoxide
B nitrogen
C nitrogen dioxide
D unburnt hydrocarbons
▶️Answer/Explanation
Ans: C
Questions 21
Topic -1.1 Particles in the atom and atomic radius
The diagram shows the melting points of eight elements with consecutive atomic numbers. Which element could be sodium?
▶️Answer/Explanation
Ans: C
Questions 22
Topic -3.6 Intermolecular forces, electronegativity and bond properties
The boiling points of Br₂, ICl and IBr are given in the table.
Which row explains:
• why the boiling point of ICl is greater than Br₂?
• why the boiling point of IBr is greater than ICl ? 
▶️Answer/Explanation
Ans: B
Questions 23
Topic -2.4 Reacting masses and volumes (of solutions and gases)
A solution contains both Mg²⁺(aq) and Sr²⁺(aq) at the same concentration. The solution is divided into two equal portions. Aqueous sodium hydroxide is added dropwise to one portion. Dilute sulfuric acid is added dropwise to the other portion. Which row is correct?
▶️Answer/Explanation
Ans: B
Questions 24
Topic -13.4 Isomerism: structural isomerism and stereoisomerism
Structural isomerism and stereoisomerism should be considered when answering this question. If a molecule contains two non-identical chiral carbon atoms, four optical isomers exist. How many isomers are there with:
• molecular formula \(C_7H_{14}O\) and
• a five-membered ring and
• a tertiary alcohol group?
A 4
B 5
C 9
D 13
▶️Answer/Explanation
Ans: C
Questions 25
Topic -13.4 Isomerism: structural isomerism and stereoisomerism
Which reagent will react with pentan-3-ol to give a mixture of stereoisomers?
A acidified potassium dichromate
B concentrated sulfuric acid
C ethanoic acid in the presence of a little concentrated H₂SO₄.
D hydrogen chloride
▶️Answer/Explanation
Ans: B
Questions 26
Topic -12.1 Nitrogen and sulfur
An organic molecule W contains 3 carbon atoms. It requires 4.5 molecules of oxygen for complete combustion. What could W be?
A propane
B propanoic acid
C propanone
D propan-1-ol
▶️Answer/Explanation
Ans: D
Questions 27
Topic -13.2 Characteristic organic reactions
Which equation represents a reaction that proceeds through initiation, propagation and termination steps?
A C₄H₁₀ + Cl₂ → C₄H₉Cl + HCl
B C₅H₁₁Br + NaOH → C₅H₁₁OH + NaBr
C C₆H₁₂ + H₂O → C₆H₁₃OH
D \(C_6H_{13}CHO + HCN → C_6H_{13}CH(OH)CN\)
▶️Answer/Explanation
Ans: A
Questions 28
Topic -13.4 Isomerism: structural isomerism and stereoisomerism
Structural isomerism and stereoisomerism should be considered when answering this question. A set of isomeric hydrocarbons:
• all contain 14.3% by mass of hydrogen
• all react with bromine by addition, 0.280 g of each hydrocarbon reacting with 0.799 g of bromine.
What is the maximum number of isomeric compounds in the set?
A 1
B 3
C 4
D 5
▶️Answer/Explanation
Ans: C
Questions 29
Topic -25.2 Partition coefficients
Which row describes the solvent used and type of reaction occurring when bromoethane reacts with NaOH to form ethene?
▶️Answer/Explanation
Ans: A
Questions 30
Topic -9.1 Periodicity of physical properties of the elements in Period 3
Which row describes the type of reaction that occurs when propan-1-ol reacts to form the named carbon-containing product?
▶️Answer/Explanation
Ans: C
Questions 31
Topic -21.1 Organic synthesis
Which statement describes what happens when 2-chloro-2-methylpropane is warmed with NaOH(aq)?
A This secondary halogenoalkane reacts by a mixture of an \(S_N1\) and an \(S_N2\) mechanism.
B This secondary halogenoalkane reacts only by an \(S_N2\) mechanism.
C This tertiary halogenoalkane reacts mostly by an \(S_N1\) mechanism.
D This tertiary halogenoalkane does not react with hydroxide ions under these conditions.
▶️Answer/Explanation
Ans: C
Questions 32
Topic -13.4 Isomerism: structural isomerism and stereoisomerism
How many structurally isomeric secondary alcohols are there with the molecular formula \(C_5H_{12}O\)?
A 1
B 2
C 3
D 4
▶️Answer/Explanation
Ans: C
Questions 33
Topic -29.1 Formulas, functional groups and the naming of organic compounds
Which reagent:
• can confirm the presence of a carbonyl group in an organic compound
• does not distinguish between aldehydes and ketones?
A acidified K₂Cr₂O₇
B 2,4-DNPH reagent
C Fehling’s reagent
D \(LiAl H_4\)
▶️Answer/Explanation
Ans: B
Questions 34
Topic -13.4 Isomerism: structural isomerism and stereoisomerism
Which compound gives a positive test with alkaline aqueous iodine and does not show optical isomerism?
A CH₃COCH₂CH₂OH
B CH₃CH₂CH(OH)CHO
C CH₃COCH(OH)CH₃
D (CH₃)₂C(OH)CHO
▶️Answer/Explanation
Ans: A
Questions 35
Topic -2.4 Reacting masses and volumes (of solutions and gases)
Two samples of compound X were treated separately with different reagents which were added in excess. The products of these two reactions are shown.
Which reagents could be used for reaction 1 and reaction 2?
▶️Answer/Explanation
Ans: D
Questions 36
Topic -1.1 Organic synthesis
Which method could produce butanoic acid?
A an acid–base reaction involving CH₃CH₂CH₂CO₂Na
B the hydrolysis of CH₃CH₂CH₂CH₂CN
C the acidic hydrolysis of CH₃CH₂COOCH₂CH₂CH₃
D the oxidation of CH₃CH₂CH₂OH
▶️Answer/Explanation
Ans: A
Questions 37
Topic -18.2 Esters
Which ester may be hydrolysed to produce two products, one of which may be reduced to the other?
A CH₃CH₂CO₂CH₃
B CH₃CH(CH₃)CO₂CH₂CH(CH₃)₂
C CH₃CH₂CO₂CH(CH₃)₂
D (CH₃)₂CHCO₂CH(CH₃)₂
▶️Answer/Explanation
Ans: B
Questions 38
Topic -18.2 Esters
Two compounds, X and Y, are mixed and a little concentrated H₂SO₄ is added. Ester Z is found in the resulting mixture of products.
Which two compounds could be X and Y? 
▶️Answer/Explanation
Ans: C
Questions 39
Topic -20.1 Addition polymerisation
The diagram shows a section of a polymer molecule.
–CH₂–CH=CH–CH₂–CH₂–CH=CH–CH₂–
Which monomer will produce this polymer?
A CH₂=CH₂
B CH₃CH=CH₂
C CH₃CH=CHCH₃
D CH₂=CH–CH=CH₂
▶️Answer/Explanation
Ans: D
Questions 40
Topic -1.2 Isotopes
There are two naturally occuring isotopes of bromine. One isotope has 44 neutrons. The other isotope has 46 neutrons. Ignoring fragments, how many peaks are there in the mass spectrum of tribromomethane, \(^{12}C^1HBr_3\)?
A 2
B 3
C 4
D 6
▶️Answer/Explanation
Ans: C