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Questions 1

Topic – 2.3 Formulas

Which pair of formulae is correct?
A Ag₂CO₃ and (NH₄)₃NO₃
B \(K_2HCO_3\) and \(Zn_3(PO_4)_2\)
C AgHCO₃ and K₃PO₄
D \(ZnCO_3\) and \((NH_4)_2PO4\)

▶️Answer/Explanation

Ans: C

Questions 2

Topic – 2.1 Relative masses of atoms and molecules

How many molecules are present in 62 g of solid white phosphorus, \(P_4\)?
A L

B 2L

C \(\frac{L}{2}\)

D\(\frac{L}{4}\)

▶️Answer/Explanation

Ans: C

Questions 3

Topic – 1.4 Ionisation energy

The first eight successive ionisation energies for two elements of Period 3 of the Periodic Table are shown in the graphs.

What is the formula of the ionic compound formed from these elements?
A MgCl₂

BaBr₂

C Na₂S

D \(K_2Se\)

▶️Answer/Explanation

Ans: A

Questions 4

Topic – 1.3 Electrons, energy levels and atomic orbitals

In which pairs are both species free radicals?
1 Cl and O
2 \(Cl^–\) and \(O_2^–\)
3 Cl and \(O^–\)
4 Cl⁻and O₂⁺
A 1, 3 and 4

B 1 and 3 only

C 1 only

D 2 only

▶️Answer/Explanation

Ans: A

Questions 5

Topic – 3.5 Shapes of molecules

Which shape is correctly predicted by VSEPR theory?

▶️Answer/Explanation

Ans: C

Questions 6

Topic – 3.7 Dot-and-cross diagrams

In which species does the underlined atom have an incomplete outer shell?
A \(BF_3\)

B \(CH_3^–\)

C \(F_2O\)

D \(H_3O^+\)

▶️Answer/Explanation

Ans: A

Questions 7

Topic – 4.1 The gaseous state: ideal and real gases and pV = nRT

In this question it should be assumed that nitrogen behaves as an ideal gas under the conditions stated. Which volume is occupied by 1.00 g of nitrogen at 50.0°C and at a pressure of 120 kPa?
A 0.124 dm³

B 0.799 dm³

C 1.60 dm³

D 22.4 dm³

▶️Answer/Explanation

Ans: B

Questions 8

Topic – 4.2 Bonding and structure

Consider the following four compounds.
1 (CH₃)₃CH
2 CH₃CH₂CH₂OH
3 CH₃CH₂CH₂SH
4 CH₃CH₂CH₂CH₃
What is the order of increasing boiling point of the compounds (lowest first)?
A 1 → 4 → 2 → 3
B 1 → 4 → 3 → 2
C 4 → 1 → 2 → 3
D 4 → 1 → 3 → 2

▶️Answer/Explanation

Ans: B

Questions 9

Topic – 5.2 Hess’s law

Ethane can react with fluorine to produce 1,2-difluoroethane, C₂H₄F₂.

What is the bond energy of the C–F bond in 1,2-difluoroethane?
A \(407 kJ mol^{–1}\)

B \(474 kJ mol^{–1}\)

C \(486 kJ mol^{–1}\)

D \(972 kJ mol^{–1}\)

▶️Answer/Explanation

Ans: C

Questions 10

Topic – 5.1 Enthalpy change, ΔH

Which equation has an enthalpy change equal to the standard enthalpy of formation of sodium oxide?
A \(Na(s) + \frac{1}{4} O_2(g) → \frac{1}{2}Na_2O(s)\)
B \(Na(s) + O_2(g) → Na_2O(s)\)
C \(2Na(s) + \frac{1}{2}O_2(g) → Na_2O(s)\)
D \(4Na(s) + O_2(g) → 2Na_2O(s)\)

▶️Answer/Explanation

Ans: C

Questions 11

Topic – 7.1 Chemical equilibria: reversible reactions, dynamic equilibrium

Nitrogen dioxide reacts with water.
\(2NO_2 + H_2O → HNO_2 + HNO_3\)
Which statement about this reaction is correct?
A Both products are formed because oxygen atoms gain electrons.
B Nitrogen atoms undergo disproportionation.
C The oxidation number of hydrogen is increased.
D Water acts as an oxidising agent.

▶️Answer/Explanation

Ans: B

Questions 12

Topic – 2.4 Reacting masses and volumes (of solutions and gases)

Phosphorus reacts with concentrated sulfuric acid to produce phosphoric acid, sulfur dioxide and water.
aH₂SO₄ + bP → cH₃PO₄ + dSO₂ + eH₂O
a, b, c, d and e are all whole numbers. The equation can be balanced by using oxidation numbers. What is the value of the sum a + b + c + d + e?
A 10

B 14

C 15

D 16

▶️Answer/Explanation

Ans: D

Questions 13

Topic – 3.6 Intermolecular forces, electronegativity and bond properties

The volume of ammonia produced against time is measured in two experiments.
\(N_2(g) + 3H_2(g) → 2NH_3(g) \)∆H = –92 \(kJ mol^{–1}\)
In experiment 1, 3 mol of H2(g) and 1 mol of N2(g) react together at 45°C and a pressure of 200 atm. A graph showing the volume of ammonia produced against time is plotted. Experiment 2 is then performed. Experiment 2 differs from experiment 1 in one condition only.

How does experiment 2 differ from experiment 1?
A An iron catalyst is present in experiment 2.
B 2 mol of helium gas is present in the reaction mixture in experiment 2.
C A pressure of 250 atm is used in experiment 2.
D A temperature of 600°C is used in experiment 2.

▶️Answer/Explanation

Ans: D

Questions 14

Topic – 7.1 Chemical equilibria: reversible reactions, dynamic equilibrium

Which reaction has an equilibrium constant, \(K_p\), that has no units?
A \(H_2(g) + I_2(g) \rightleftharpoons 2HI(g)\)
B \(3H_2(g) + N_2(g) \rightleftharpoons 2NH_3(g)\)
C\( 2NO_2(g) \rightleftharpoons N_2O_4(g)\)
D \(2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)\)

▶️Answer/Explanation

Ans: A

Questions 15

Topic – 8.2 Effect of temperature on reaction rates and the concept of activation energy

Gas Q decomposes slowly at room temperature.
Q(g) → X(g) + Z(g)
The Boltzmann distribution curve for gas Q at room temperature is shown.

Which change occurs when a catalyst is added to gas Q?
A The peak of the curve moves to the right on the diagram.
B The number of particles with enough energy to decompose increases.
C The kinetic energy of the unreacted particles increases.
D The value of Ea decreases, moving the vertical dotted line to the right on the diagram.

▶️Answer/Explanation

Ans: B

Questions 16

Topic – 9.1 Periodicity of physical properties of the elements in Period 3

Which statement is correct?
A Aluminium chloride has a giant ionic lattice of Al³⁺ and Cl– ions.
B Sodium chloride dissolves in water, forming hydrogen chloride and sodium hydroxide.
C The strong covalent bonds in silicon chloride prevent it from reacting with water.
D When phosphorus(V) chloride is added to water, the resulting solution conducts electricity.

▶️Answer/Explanation

Ans: D

Questions 17

Topic – 10.1 Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds

A mixture of calcium carbonate, calcium nitrate, strontium carbonate and strontium nitrate is thermally decomposed. The decomposition reaction of each substance goes to completion. Each substance is anhydrous. How many different products are formed?
A 4

B 5

C 7

D 8

▶️Answer/Explanation

Ans: B

Questions 18

Topic – 7.2 Brønsted–Lowry theory of acids and bases

W is a solid that reacts with water to produce an alkaline solution. The addition of two drops of dilute H₂SO₄ to this alkaline solution produces a white precipitate. What could be the identity of solid W?
A magnesium hydroxide
B magnesium oxide
C barium oxide
D phosphorus oxide

▶️Answer/Explanation

Ans: C

Questions 19

Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)

Chlorine gas is reacted with cold aqueous sodium hydroxide. Which statement is correct for this reaction?
A Chlorine is both oxidised and reduced.
B Chlorine is neither oxidised nor reduced.
C Chlorine is oxidised but not reduced.
D Chlorine is reduced but not oxidised.

▶️Answer/Explanation

Ans: A

Questions 20

Topic – 3.4 Covalent bonding and coordinate (dative covalent) bonding

Sodium is added to water to form solution Y. The pH of solution Y is measured. When powdered substance X is added to solution Y, the pH falls. Which two compounds could each be substance X?
MgCl₂ and Al(OH)₃
B MgCl₂ and K₂O
C NaCl and Al(OH)₃
D NaCl and K₂O

▶️Answer/Explanation

Ans: A

Questions 21

Topic – 15.1 Halogenoalkanes

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?

▶️Answer/Explanation

Ans: D

Questions 22

Topic – 7.2 Brønsted–Lowry theory of acids and bases

Which statement describes a property of an ammonium ion?
A An aqueous ammonium ion is a weak Brønsted–Lowry base.
B Aqueous ammonium sulfate reacts with dilute hydrochloric acid to make ammonia gas.
C An ammonium ion has a pyramidal shape with an H–N–H bond angle of 107°.
D The four N–H covalent bonds in an ammonium ion are identical to each other.

▶️Answer/Explanation

Ans: D

Questions 23

Topic – 8.3 Homogeneous and heterogeneous catalysts

Catalytic converters are fitted in the exhaust systems of many cars.
Gas X:
● causes acid rain if it is released into the air
● is removed from car exhaust fumes by a catalytic converter.
What is gas X?
A carbon dioxide
B carbon monoxide
C hydrocarbon vapour
D nitrogen dioxide

▶️Answer/Explanation

Ans: D

Questions 24

Topic – 16.1 Alcohols

In the general formula of which class of compound is the ratio of hydrogen atoms to carbon atoms the highest?
A alcohols
B aldehydes
C carboxylic acids
D halogenoalkanes

▶️Answer/Explanation

Ans: A

Questions 25

Topic – 1.1 Particles in the atom and atomic radius

Which statement is correct?
A Adding sodium oxide to water gives a lower pH solution than adding silicon oxide to water.
B The oxidation state of sodium in its chloride is higher than the oxidation state of silicon in its chloride.
C The atomic radius of sodium is larger than that of silicon.
D The melting point of the chloride of sodium is lower than the melting point of the chloride of silicon.

▶️Answer/Explanation

Ans: C

Questions 26

Topic – 13.1 Formulas, functional groups and the naming of organic compounds

Z is a gaseous hydrocarbon which has a density of 3.50 × 10⁻³ g/cm³ under room conditions. Z reacts with an excess of hot concentrated acidified KMnO₄. Only one type of carboxylic acid is formed in this reaction. What is Z?
A but-2-ene
B 2,3-dimethylbut-2-ene
C hex-2-ene
D hex-3-ene

▶️Answer/Explanation

Ans: D

Questions 27

Topic – 16.1 Alcohols

Compound X can be oxidised to compound Y. Compound Y gives a yellow precipitate with alkaline \(I_2\)(aq). What is compound X?
A butan-1-ol
B butan-2-ol
C methylpropan-1-ol
D methylpropan-2-ol

▶️Answer/Explanation

Ans: B

Questions 28

Topic – 13.2 Characteristic organic reactions

Aqueous NaOH reacts with 1-bromopropane to give propan-1-ol. What should be included in a diagram of the first step in the mechanism?
A a curly arrow from a lone pair on the OH⁻ ion to the \(C^{δ+}\) atom of 1-bromopropane
B a curly arrow from the \(C^{δ+}\) atom of 1-bromopropane to the OH⁻ ion
C a curly arrow from the C–Br bond to the C atom
D the homolytic fission of the C–Br bond

▶️Answer/Explanation

Ans: A

Questions 29

Topic – 17.1 Aldehydes and ketones

In which reaction is the organic compound oxidised?
A CH₃CH₂CH₂CHO + Tollens’ reagent
B \(CH_3CH_2CH_2CHO\) + \(LiAlH_4\)
C CH₃CH₂CH₂OH + concentrated H₃PO₄
D \(CH_3CO_2C_2H_5\) + dilute \(H_2SO_4\)

▶️Answer/Explanation

Ans: A

Questions 30

Topic – 2.4 Reacting masses and volumes (of solutions and gases)

1 mole of each of the following four compounds is reacted separately with:
● an excess of sodium
● an excess of sodium carbonate.
Which compound produces the same volume of gas with each of the two reagents?

▶️Answer/Explanation

Ans:D

Questions 31

Topic – 33.1 Carboxylic acids

Which reaction will distinguish between propan-1-ol and propan-2-ol?
A warming with acidified KMnO₄
B warming with acidified \(K_2Cr_2O_7\)
C dehydration, followed by reaction with Br₂(aq)
D mild oxidation, followed by reaction with Fehling’s reagent

▶️Answer/Explanation

Ans: D

Questions 32

Topic – 13.4 Isomerism: structural isomerism and stereoisomerism

Compound T has the skeletal formula shown.

Which structure is a structural isomer of compound T?

▶️Answer/Explanation

Ans: D

Questions 33

Topic – 16.1 Alcohols

The diagram shows a simplified structure of coenzyme \(Q_{10}\).

Which row describes the structure of coenzyme \(Q_{10}\) correctly?

▶️Answer/Explanation

Ans: D

Questions 34

Topic – 13.3 Shapes of organic molecules; σ and π bonds

The molecule of limonene, \(C_{10}H_{16}\), contains a 6-membered ring. This is the only cyclic component in its structure. Which volume of hydrogen, at room conditions, is required to react completely with the C=C double bonds in one mole of limonene?
A 12 dm³

B 24 dm³

C 48 dm³

D 72 dm³

▶️Answer/Explanation

Ans: C

Questions 35

Topic – 2.3 Formulas

1-bromopropane reacts with hot ethanolic NaOH. What is the molecular formula of the product in this reaction?
A \(C_3H_6\)

B \(C_3H_8\)

C \(C_3H_7O\)

D \(C_3H_8O\)

▶️Answer/Explanation

Ans: A

Questions 36

Topic – 13.4 Isomerism: structural isomerism and stereoisomerism

A sample of pent-2-en-4-ol, \(C_5H_{10}O\), contains all the possible stereoisomers of this compound. How many stereoisomers are there in the sample?
A 2

B 3

C 4

D 5

▶️Answer/Explanation

Ans: C

Questions 37

Topic – 13.4 Isomerism: structural isomerism and stereoisomerism

Which pair of reagents reacts to form a product with a chiral carbon atom?
A CH₃CH=CH₂ + HBr
B(CH₃)₂C=O + NaBH₄
C CH₃CH₂CHO + HCN
D \(CH_3COOH + CH_3CH_2OH\)

▶️Answer/Explanation

Ans: C

Questions 38

Topic – 13.1 Formulas, functional groups and the naming of organic compounds

The diagrams show the structures of two esters, X and Y, that are formed in ripening apples.