AQA A-Level Chemistry sample questions and answers (7405)
Guide overview All 18 topics Sample questions Papers and weighting Look inside Questions and answers
54 sample questions and answers
Taken from every topic of AQA A-Level Chemistry, specification 7405. The full guide has 2,442.
Paper 1, Paper 2, Paper 3
Atomic Structure
89 questions in the guide, across 7 subtopics. More from this topic
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Fundamental Particles
What is the relative mass of a proton?
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1 -
Fundamental Particles
Where in an atom are neutrons located?
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In the nucleus -
Mass Number and Isotopes
How do you determine the number of electrons in a neutral atom?
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The number of electrons equals the atomic number (same as the number of protons).
Paper 1, Paper 2, Paper 3
Amount of Substance
118 questions in the guide, across 8 subtopics. More from this topic
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Relative Atomic and Molecular Mass
How is relative molecular mass calculated from a molecular formula?
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By adding together the relative atomic masses of all atoms present in the molecular formula. -
The Mole and the Avogadro Constant
How is the number of moles of a substance calculated from its mass?
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Moles = mass ÷ Mᵣ -
The Ideal Gas Equation
What does T represent in the ideal gas equation?
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Temperature
Paper 1, Paper 2, Paper 3
Bonding
132 questions in the guide, across 8 subtopics. More from this topic
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Ionic Bonding
What is the formula of the carbonate ion?
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CO₃²⁻ -
Covalent, Dative Covalent and Metallic Bonding
In a dative covalent bond, what must the acceptor species possess?
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An empty orbital. -
Crystal Structures: Giant Ionic Lattices and Diamond
Under what conditions do ionic compounds conduct electricity?
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When molten or dissolved in water
Paper 1, Paper 2, Paper 3
Energetics and Thermodynamics
108 questions in the guide, across 8 subtopics. More from this topic
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Enthalpy Change and Standard Conditions
What does the term exothermic mean in relation to a reaction?
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A reaction that releases heat energy to the surroundings (negative ΔH) -
Calorimetry and Heat Change Calculations
How would you calculate the molar enthalpy change from the heat change measured in a calorimetry experiment?
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Divide the heat change (q) by the number of moles of the limiting reactant -
Hess's Law and Enthalpy Cycles
When using enthalpies of formation to calculate the enthalpy change of a reaction, what is the general formula?
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ΔH = Σ ΔfH(products) − Σ ΔfH(reactants)
Paper 1, Paper 2, Paper 3
Kinetics
133 questions in the guide, across 9 subtopics. More from this topic
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Collision Theory and Activation Energy
Besides having sufficient energy, what other requirement must be met for a successful collision?
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The particles must collide with the correct orientation. -
Maxwell-Boltzmann Distribution and the Effect of Temperature
How does the position of the peak of a Maxwell-Boltzmann distribution relate to the mean energy?
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The peak (most probable energy) is at a lower energy than the mean energy -
Effect of Concentration and Pressure, and Catalysts
For a gaseous reaction, what happens to the collision frequency if the pressure is halved?
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The collision frequency decreases as particles are further apart on average.
Paper 1, Paper 2, Paper 3
Chemical Equilibria
80 questions in the guide, across 5 subtopics. More from this topic
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Dynamic Equilibrium and Le Chatelier's Principle
What happens to the position of equilibrium when the concentration of a product is removed?
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The position of equilibrium shifts to the right (towards products) to replace the removed product. -
Dynamic Equilibrium and Le Chatelier's Principle
How does a catalyst affect the rate at which equilibrium is reached?
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A catalyst increases the rate at which equilibrium is reached. -
Industrial Compromise Conditions
Why is a very high pressure not always used in industrial processes even when it would favour the products?
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Very high pressures are expensive to maintain and require stronger equipment, increasing costs.
Paper 1, Paper 2, Paper 3
Redox and Electrochemistry
109 questions in the guide, across 7 subtopics. More from this topic
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Redox: Definitions and the Rules for Oxidation States
What oxidation state is assigned to uncombined elements?
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Zero -
Redox: Definitions and the Rules for Oxidation States
What oxidation state is usually assigned to hydrogen in compounds?
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+1 -
Redox: Identifying Oxidation and Reduction in a Reaction
What change in oxidation state indicates that an element has been reduced?
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A decrease in oxidation state
Paper 1, Paper 2, Paper 3
Acids and Bases
117 questions in the guide, across 7 subtopics. More from this topic
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Brønsted-Lowry Acid-Base Equilibria
What is a conjugate acid?
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The species formed when a base accepts a proton -
Brønsted-Lowry Acid-Base Equilibria
Explain why water is described as amphoteric in the Brønsted-Lowry sense.
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Water can donate a proton to act as an acid, forming OH⁻, or accept a proton to act as a base, forming H₃O⁺ -
The pH Scale and Strong Acids
What is a strong acid?
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An acid that completely dissociates in aqueous solution
Paper 1, Paper 3
Periodicity and Group Chemistry
218 questions in the guide, across 16 subtopics. More from this topic
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s, p, d and f Block Classification
Which subshell is being filled in p-block elements?
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The p subshell -
Group 2 Trends in Atomic Radius, Ionisation Energy and Melting Point
Explain why first ionisation energy decreases down Group 2.
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The outer electron is further from the nucleus due to additional electron shells, there is greater shielding from inner electrons, so less energy is required to remove the outer electron despite the increased nuclear charge. -
Solubility Trends of Group 2 Hydroxides
What is the agricultural use of calcium hydroxide?
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Calcium hydroxide is used to neutralise acidic soils.
Paper 1, Paper 3
Period 3 Elements and Their Oxides
92 questions in the guide, across 8 subtopics. More from this topic
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Reactions of Na and Mg with Water
What is observed when magnesium reacts with cold water?
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Very slow reaction with few bubbles of gas produced; a white precipitate/coating of magnesium hydroxide forms on the surface. -
Period 3 Elements with Oxygen: The Oxides Formed and Their Bonding
What is the formula of the oxide formed when silicon reacts with oxygen?
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SiO₂ -
Period 3 Elements with Oxygen: Structures and Oxidation States
What type of structure do phosphorus(V) oxide, sulfur dioxide and sulfur trioxide have?
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Simple molecular structures
Paper 1, Paper 3
Transition Metals
324 questions in the guide, across 19 subtopics. More from this topic
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General Properties of Transition Metals
What is a ligand?
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A molecule or ion that donates an electron pair to a transition metal, forming a coordinate bond -
Complex Ions: Why a Species Can Act as a Ligand, and Coordination Number
What determines whether a ligand is monodentate, bidentate, or multidentate?
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The number of atoms in the ligand that have lone pairs capable of forming coordinate bonds with the metal ion. -
Substitution Reactions with Bidentate and Multidentate Ligands
What type of reaction occurs when a bidentate or multidentate ligand replaces monodentate ligands in a complex?
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A ligand substitution reaction.
Paper 2, Paper 3
Introduction to Organic Chemistry
106 questions in the guide, across 8 subtopics. More from this topic
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Nomenclature and Formula Representations
What is the purpose of a structural formula?
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To show how atoms are arranged and connected in a molecule. -
Homologous Series and General Formulae
What is the general formula for alcohols?
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CₙH₂ₙ₊₁OH or CₙH₂ₙ₊₂O -
IUPAC Naming: Stems, Prefixes and Suffixes
What suffix is used to name an alkene?
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-ene
Paper 2, Paper 3
Hydrocarbons
118 questions in the guide, across 7 subtopics. More from this topic
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Alkanes, Fractional Distillation and Cracking
What property of the components allows fractional distillation to separate them?
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Different boiling points -
Alkanes, Fractional Distillation and Cracking
What type of catalyst is used in catalytic cracking?
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Zeolite catalyst -
Combustion of Alkanes and Pollutants
How are NOₓ pollutants formed in internal combustion engines?
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Nitrogen and oxygen from the air react at the high temperatures inside the engine
Paper 2, Paper 3
Halogenoalkanes, Alcohols and Organic Analysis
175 questions in the guide, across 12 subtopics. More from this topic
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Nucleophilic Substitution of Halogenoalkanes
In the reaction of a halogenoalkane with cyanide ions, what is the organic product?
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A nitrile -
Effect of Bond Enthalpy on Reaction Rate
Why do iodoalkanes react faster than chloroalkanes in nucleophilic substitution reactions?
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The C-I bond has a lower bond enthalpy than the C-Cl bond, so it is easier to break. -
CFCs and Ozone Depletion
What role do chlorine atoms play in the decomposition of ozone?
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They catalyse the decomposition of ozone
Paper 2, Paper 3
Carbonyls, Carboxylic Acids and Derivatives
165 questions in the guide, across 12 subtopics. More from this topic
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Oxidation of Aldehydes and Distinguishing Tests
What is the positive result when Fehling's solution reacts with an aldehyde?
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A brick-red precipitate forms -
Reduction of Carbonyls with NaBH4
If propanal is reduced with NaBH₄, what is the organic product?
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Propan-1-ol -
Hazards of KCN and Formation of Enantiomers
Why does the reaction of an aldehyde with KCN followed by dilute acid produce a mixture of enantiomers?
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The planar carbonyl group can be attacked equally from either side by the cyanide nucleophile, producing both enantiomers in equal amounts.
Paper 2, Paper 3
Aromatic Chemistry and Amines
84 questions in the guide, across 7 subtopics. More from this topic
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Bonding and Stability of Benzene
What effect does the delocalisation of electrons have on the stability of benzene?
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It makes benzene more stable -
Bonding and Stability of Benzene
How does the enthalpy of hydrogenation of benzene compare to the expected value for cyclohexa-1,3,5-triene?
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The enthalpy of hydrogenation of benzene is less exothermic than expected for cyclohexa-1,3,5-triene, indicating benzene is more stable -
Electrophilic Substitution: Nitration
Write the equation for the generation of the nitronium ion from the nitrating mixture.
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HNO₃ + H₂SO₄ → NO₂⁺ + HSO₄⁻ + H₂O
Paper 2, Paper 3
Polymers, Amino Acids, Proteins and DNA
136 questions in the guide, across 11 subtopics. More from this topic
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Condensation Polymers: Polyesters
Name a common polyester used as a textile fibre.
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Terylene -
Condensation Polymers: Polyamides
What is the name of the polyamide formed from hexanedioic acid and 1,6-diaminohexane?
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Nylon 6,6 -
Intermolecular Forces in Condensation Polymers
What functional group in polyamides allows for hydrogen bonding?
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The amide link (containing C=O and N-H groups)
Paper 2, Paper 3
Organic Synthesis, Nmr and Chromatography
138 questions in the guide, across 9 subtopics. More from this topic
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Multi-Step Synthesis Routes
When devising a multi-step synthesis, which reactions should you draw on?
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Only reactions from the A-level course you have already met -
Green Chemistry Principles in Synthesis Design
Why do addition reactions have high atom economy?
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All atoms from the reactants are incorporated into a single product with no by-products -
Principles of NMR and the Delta Scale
What symbol is used to represent chemical shift in NMR spectroscopy?
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δ (delta)
AQA A-Level Chemistry Active Recall Guide
The other 2,388 questions, with the answers printed after each section.