Edexcel A-Level Chemistry 2027 Predicted Practice Paper — Paper 1

Answer ALL questions. Write your answers in the spaces provided. You must write down all the stages in your working.

Section A

Multiple choice. Answer ALL questions.

• 1

  Question SECTION-A1 (1 mark)

  A sample of chlorine consists of 75% Cl-35 and 25% Cl-37 by number of atoms. What is the relative atomic mass of this chlorine sample?

  A. 35.0B. 35.5C. 36.0D. 36.5

  (Total for Question SECTION-A1 is 1 mark)
• 2

  Question SECTION-A2 (1 mark)

  Which species is isoelectronic with the fluoride ion, F^-, having 10 electrons, but is a positive ion formed by a Period 3 metal losing one electron?

  A. Na+B. Mg2+C. Cl^-D. K+

  (Total for Question SECTION-A2 is 1 mark)
• 3

  Question SECTION-A3 (1 mark)

  Which element has the highest first ionisation energy?

  A. NaB. MgC. AlD. P

  (Total for Question SECTION-A3 is 1 mark)
• 4

  Question SECTION-A4 (1 mark)

  What is the shape and bond angle of a molecule of ammonia, NH3?

  A. Trigonal planar, 120 degreesB. Trigonal pyramidal, 107 degreesC. Tetrahedral, 109.5 degreesD. Bent, 104.5 degrees

  (Total for Question SECTION-A4 is 1 mark)
• 5

  Question SECTION-A5 (1 mark)

  Which of the following compounds contains ionic bonding only?

  A. CO2B. NaClC. NH4ClD. H2O

  (Total for Question SECTION-A5 is 1 mark)
• 6

  Question SECTION-A6 (1 mark)

  The enthalpy change for a reaction is -92 kJ mol^-1. Which statement is correct?

  A. The reaction is endothermic and absorbs energyB. The reaction is exothermic and releases 92 kJ per mole of reactionC. The products have more energy than the reactantsD. The activation energy is 92 kJ mol^-1

  (Total for Question SECTION-A6 is 1 mark)
• 7

  Question SECTION-A7 (1 mark)

  Which halogen is the strongest oxidising agent?

  A. FluorineB. ChlorineC. BromineD. Iodine

  (Total for Question SECTION-A7 is 1 mark)
• 8

  Question SECTION-A8 (1 mark)

  0.50 mol of a gas occupies what volume at room temperature and pressure (molar volume = 24.0 dm^3 mol^-1)?

  A. 6.0 dm^3B. 12.0 dm^3C. 24.0 dm^3D. 48.0 dm^3

  (Total for Question SECTION-A8 is 1 mark)
• 9

  Question SECTION-A9 (1 mark)

  Which type of isomerism is shown by butan-1-ol and butan-2-ol?

  A. Chain isomerismB. Position isomerismC. Functional group isomerismD. E/Z isomerism

  (Total for Question SECTION-A9 is 1 mark)
• 10

  Question SECTION-A10 (1 mark)

  What is the oxidation state of manganese in the manganate(VII) ion, MnO4^-?

  A. +2B. +4C. +6D. +7

  (Total for Question SECTION-A10 is 1 mark)
• 11

  Question SECTION-A11 (1 mark)

  Which reagent and conditions convert a primary alcohol to a carboxylic acid?

  A. Acidified K2Cr2O7, distil immediatelyB. Excess acidified K2Cr2O7, heat under refluxC. Concentrated H2SO4, heatD. NaBH4 in aqueous solution

  (Total for Question SECTION-A11 is 1 mark)
• 12

  Question SECTION-A12 (1 mark)

  Which of the following will increase the rate of a reaction without being consumed and without altering the position of equilibrium?

  A. Increasing temperatureB. Adding a catalystC. Increasing concentrationD. Increasing pressure

  (Total for Question SECTION-A12 is 1 mark)
• 13

  Question SECTION-A13 (1 mark)

  The equilibrium N2(g) + 3H2(g) <=> 2NH3(g) is exothermic. Which change increases the equilibrium yield of ammonia?

  A. Increasing temperatureB. Decreasing pressureC. Increasing pressureD. Adding a catalyst

  (Total for Question SECTION-A13 is 1 mark)
• 14

  Question SECTION-A14 (1 mark)

  Which compound produces a white precipitate with acidified silver nitrate solution that dissolves in dilute ammonia?

  A. Sodium chlorideB. Sodium bromideC. Sodium iodideD. Sodium fluoride

  (Total for Question SECTION-A14 is 1 mark)
• 15

  Question SECTION-A15 (1 mark)

  How many peaks would you expect in the low-resolution proton (1H) NMR spectrum of ethanol, CH3CH2OH?

  A. 1B. 2C. 3D. 4

  (Total for Question SECTION-A15 is 1 mark)
• 16

  Question SECTION-A16 (1 mark)

  Which statement about the reaction of Group 2 metals with water going down the group (Mg to Ba) is correct?

  A. Reactivity decreasesB. Reactivity increasesC. Reactivity stays the sameD. The metals become less easily oxidised

  (Total for Question SECTION-A16 is 1 mark)
• 17

  Question SECTION-A17 (1 mark)

  A buffer solution is made from a weak acid HA and its sodium salt NaA. Adding a small amount of strong acid causes which species to react with the added H+?

  A. HA moleculesB. A^- ionsC. Na+ ionsD. Water molecules only

  (Total for Question SECTION-A17 is 1 mark)
• 18

  Question SECTION-A18 (1 mark)

  Which of these organic reactions is an example of electrophilic addition?

  A. Bromination of benzeneB. Reaction of ethene with bromineC. Free-radical substitution of methaneD. Nucleophilic substitution of bromoethane by hydroxide

  (Total for Question SECTION-A18 is 1 mark)
• 19

  Question SECTION-A19 (1 mark)

  The rate equation for a reaction is rate = k[A][B]^2. What is the overall order of reaction?

  A. First orderB. Second orderC. Third orderD. Zero order

  (Total for Question SECTION-A19 is 1 mark)
• 20

  Question SECTION-A20 (1 mark)

  Which standard electrode potential combination gives the most feasible (largest positive EMF) spontaneous reaction? Given: Zn2+/Zn = -0.76 V, Cu2+/Cu = +0.34 V, Ag+/Ag = +0.80 V.

  A. Zn with Cu2+B. Cu with Ag+C. Zn with Ag+D. Cu with Zn2+

  (Total for Question SECTION-A20 is 1 mark)

Section B

Short-answer and structured questions. Answer ALL questions.

• 1

  Question SECTION-B1 (6 marks)

  Nickel forms the complex ion [Ni(H2O)6]^2+ in aqueous solution. (a) State the shape and coordination number of this ion. (b) When excess concentrated ammonia is added, a new complex [Ni(NH3)6]^2+ forms. Explain, in terms of the type of reaction occurring, why this substitution takes place and state one observation. (c) Explain what is meant by the term 'ligand' and describe the bonding between a single ligand and the nickel ion.

  (Total for Question SECTION-B1 is 6 marks)
• 2

  Question SECTION-B2 (7 marks)

  Propene (CH3CH=CH2) reacts with hydrogen bromide, HBr. (a) Name the type of mechanism and state what HBr acts as. (b) Describe the mechanism using curly arrows, identifying the intermediate formed. (c) State and explain, using Markovnikov's rule, which of the two possible products is the major product.

  (Total for Question SECTION-B2 is 7 marks)
• 3

  Question SECTION-B3 (6 marks)

  A student determines the enthalpy change of combustion of ethanol using a spirit burner to heat water. Data: mass of ethanol burned = 0.92 g; mass of water heated = 150 g; temperature rise = 22.0 degrees C. (Specific heat capacity of water = 4.18 J g^-1 K^-1; Mr of ethanol = 46.0.) (a) Calculate the heat energy transferred to the water. (b) Calculate the enthalpy change of combustion of ethanol in kJ mol^-1. (c) Explain why the experimental value is less exothermic (less negative) than the data-book value.

  (Total for Question SECTION-B3 is 6 marks)
• 4

  Question SECTION-B4 (6 marks)

  Consider the equilibrium: 2SO2(g) + O2(g) <=> 2SO3(g), DeltaH = -197 kJ mol^-1. (a) Write the expression for the equilibrium constant Kc. (b) State and explain the effect on the value of Kc and on the yield of SO3 of increasing the temperature. (c) State the effect of adding a vanadium(V) oxide catalyst on the value of Kc and give a reason.

  (Total for Question SECTION-B4 is 6 marks)
• 5

  Question SECTION-B5 (7 marks)

  The rate of the reaction between substances X and Y was investigated. Initial-rate data: Expt 1: [X] = 0.10, [Y] = 0.10, rate = 2.0 x 10^-3 mol dm^-3 s^-1. Expt 2: [X] = 0.20, [Y] = 0.10, rate = 8.0 x 10^-3. Expt 3: [X] = 0.20, [Y] = 0.20, rate = 8.0 x 10^-3. (a) Determine the order with respect to X and with respect to Y, showing your reasoning. (b) Write the rate equation. (c) Calculate the value of the rate constant k, including its units.

  (Total for Question SECTION-B5 is 7 marks)
• 6

  Question SECTION-B6 (7 marks)

  Ethanoic acid is a weak acid with Ka = 1.8 x 10^-5 mol dm^-3 at 298 K. (a) Explain what is meant by a 'weak acid'. (b) Calculate the pH of a 0.100 mol dm^-3 solution of ethanoic acid, stating one assumption you make. (c) A buffer is made by mixing this acid with sodium ethanoate. Explain, with an equation, how the buffer resists a decrease in pH when a small amount of alkali (OH^-) is added.

  (Total for Question SECTION-B6 is 7 marks)
• 7

  Question SECTION-B7 (6 marks)

  Bromoethane (CH3CH2Br) can be converted to ethanol and to ethylamine. (a) Give the reagent and conditions for converting bromoethane to ethanol, and name the mechanism. (b) Give the reagent and conditions for converting bromoethane to ethylamine, and explain why an excess of this reagent is used. (c) Explain why iodoethane reacts faster than bromoethane in nucleophilic substitution.

  (Total for Question SECTION-B7 is 6 marks)
• 8

  Question SECTION-B8 (7 marks)

  A 25.0 cm^3 sample of aqueous iron(II) ions was titrated with 0.0200 mol dm^-3 acidified potassium manganate(VII), requiring 23.40 cm^3 to reach the end point. The equation is: MnO4^- + 8H+ + 5Fe^2+ -> Mn^2+ + 4H2O + 5Fe^3+. (a) Describe the colour change at the end point and explain why no indicator is needed. (b) Calculate the concentration of Fe^2+ ions in mol dm^-3. (c) State and explain the effect on the calculated Fe^2+ concentration if the conical flask still contained a little distilled water from rinsing.

  (Total for Question SECTION-B8 is 7 marks)

Section C

Extended writing. Answer ALL questions.

• 1

  Question SECTION-C1 (6 marks)

  Describe how a Born-Haber cycle can be used to determine the lattice enthalpy of formation of sodium chloride, NaCl. In your answer, name the enthalpy changes involved (atomisation, ionisation energy, electron affinity, enthalpy of formation), state whether each is typically exothermic or endothermic, and explain how Hess's law allows the lattice enthalpy to be calculated. (6 marks)

  (Total for Question SECTION-C1 is 6 marks)
• 2

  Question SECTION-C2 (6 marks)

  Explain how the entropy change (DeltaS) and enthalpy change (DeltaH) of a reaction together determine whether it is thermodynamically feasible. Refer to the Gibbs free energy relationship, discuss the effect of temperature, and use the decomposition of calcium carbonate (CaCO3(s) -> CaO(s) + CO2(g), which is endothermic with a positive entropy change) as an example. (6 marks)

  (Total for Question SECTION-C2 is 6 marks)
• 3

  Question SECTION-C3 (6 marks)

  Aromatic compounds undergo electrophilic substitution rather than addition. Explain the bonding in benzene that accounts for its stability and its preference for substitution reactions, and describe the mechanism of the nitration of benzene, including how the electrophile is generated. (6 marks)

  (Total for Question SECTION-C3 is 6 marks)