Structure, Bonding and Introduction to Organic Chemistry

Worked examples (8)

• 1Writing formulae of simple ionic compounds (2 marks)
• 2Formulae with polyatomic ions and brackets (2 marks)
• 3Calculating a relative formula mass (2 marks)
• 4Empirical formula from percentage composition (4 marks)
• 5Empirical formula from reacting masses (4 marks)
• 6Molecular formula from empirical formula and Mr (3 marks)
• 7Empirical and molecular formula from combustion data (6 marks)
• 8Water of crystallisation in a hydrated salt (5 marks)

Model answers (9)

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• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer 9

Worked examples (8)

• 1Balancing a simple equation (2 marks)
• 2Adding state symbols (2 marks)
• 3Balancing complete combustion of a hydrocarbon (3 marks)
• 4Ionic equation for a precipitation reaction (4 marks)
• 5Net ionic equation for neutralisation (4 marks)
• 6Ionic equation for metal + acid (3 marks)
• 7Balancing a redox half-equation with H⁺ and e⁻ (6 marks)
• 8Deducing an equation from reacting amounts (6 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Classifying an element into its block (2 marks)
• 2Atomic radius across Period 3 (2 marks)
• 3Defining first ionisation energy with an equation (3 marks)
• 4Explaining the general rise in first IE across a period (4 marks)
• 5The Group 2 → Group 3 dip in first IE (4 marks)
• 6The Group 5 → Group 6 dip in first IE (4 marks)
• 7Melting temperature across Period 3 (6 marks)
• 8Deducing a group from successive ionisation energies (5 marks)

Model answers (9)

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• ✓Model answer 8
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Defining an ionic bond (2 marks)
• 2Dot-and-cross diagram for sodium chloride (3 marks)
• 3Conductivity of NaCl in different states (3 marks)
• 4Dot-and-cross diagram for magnesium chloride (4 marks)
• 5Dot-and-cross diagram for magnesium oxide (4 marks)
• 6Dot-and-cross diagram for calcium fluoride (5 marks)
• 7Why ionic solids are brittle and dissolve (6 marks)
• 8Predicting relative lattice strength from charge and radius (5 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Sub-atomic particles in an isotope (2 marks)
• 2Relative mass and charge of sub-atomic particles (2 marks)
• 3Relative atomic mass from a mass spectrum (3 marks)
• 4Electron configuration of an atom and its ion (4 marks)
• 5Deducing group number from successive ionisation energies (4 marks)
• 6Predicting the mass spectrum of Cl₂ (5 marks)
• 7How a time-of-flight mass spectrometer works (6 marks)
• 8The chromium and copper configurations (6 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Moles from mass, n = m/M (2 marks)
• 2Number of particles using the Avogadro constant (2 marks)
• 3Concentration of a solution (3 marks)
• 4Volume of gas at RTP (3 marks)
• 5Finding a concentration by titration (5 marks)
• 6Limiting reagent then percentage yield (6 marks)
• 7Using the ideal gas equation pV = nRT (5 marks)
• 8Atom economy of an extraction (5 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
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• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1 Core Practical 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Defining the metallic bond (2 marks)
• 2Where the delocalised electrons come from (2 marks)
• 3Why sodium conducts electricity (3 marks)
• 4Melting-temperature trend Na → Mg → Al (4 marks)
• 5Explaining malleability of metals (4 marks)
• 6Comparing conductivity of Mg and MgO (4 marks)
• 7Why metals conduct heat well (5 marks)
• 8Why melting temperature falls down Group 1 (5 marks)

Model answers (9)

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• ✓Model answer 9

Worked examples (8)

• 1General formula and classification of alkanes (2 marks)
• 2Separating crude oil by fractional distillation (3 marks)
• 3Boiling-temperature trend down a homologous series (3 marks)
• 4Complete vs incomplete combustion equations (4 marks)
• 5Pollutants from engines and the catalytic converter (4 marks)
• 6Free-radical substitution of methane with chlorine (6 marks)
• 7Why FRS gives a mixture of products (3 marks)
• 8Effect of branching on boiling temperature (5 marks)

Model answers (9)

• ✓Model answer 1
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• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer 9

Worked examples (8)

• 1Defining a covalent bond (2 marks)
• 2Dot-and-cross diagram of Cl₂ (2 marks)
• 3What is a dative covalent bond? (3 marks)
• 4Dot-and-cross diagram of CO₂ (double bonds) (3 marks)
• 5Why the H–Cl bond is polar (4 marks)
• 6Dot-and-cross diagram of NH₄⁺ showing the dative bond (4 marks)
• 7Why CO₂ is non-polar but H₂O is polar (5 marks)
• 8Diamond and graphite — structure and properties (6 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer 9

Worked examples (8)

• 1Shape and bond angle of methane, CH₄ (2 marks)
• 2Shape and bond angle of boron trifluoride, BF₃ (2 marks)
• 3Applying VSEPR to beryllium chloride, BeCl₂ (3 marks)
• 4Comparing the bond angles of NH₃ and CH₄ (4 marks)
• 5Why the bond angle in water is 104.5° (4 marks)
• 6Deducing the shape of sulfur hexafluoride, SF₆ (4 marks)
• 7Shape and angles of phosphorus pentachloride, PCl₅ (5 marks)
• 8Predicting and ordering shapes and angles (6 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1

Worked examples (8)

• 1Naming a branched alkane (2 marks)
• 2Classifying by functional group (3 marks)
• 3Using a general formula (2 marks)
• 4Drawing structural isomers of C₄H₁₀ (3 marks)
• 5Position isomers of C₄H₉Br (4 marks)
• 6Empirical and molecular formula from composition (5 marks)
• 7Assigning E/Z with CIP priorities (5 marks)
• 8Homolytic vs heterolytic fission with curly arrows (6 marks)

Model answers (9)

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• ✓Model answer 9

Worked examples (8)

• 1General formula and the C=C double bond (2 marks)
• 2The bromine-water test for unsaturation (2 marks)
• 3Electrophilic addition of bromine to ethene (4 marks)
• 4Hydrogenation and hydration of an alkene (4 marks)
• 5Markovnikov addition of HBr to propene (5 marks)
• 6Explaining E/Z isomerism in but-2-ene (5 marks)
• 7Addition polymerisation and the repeat unit (5 marks)
• 8Environmental issues of addition polymers (4 marks)

Model answers (9)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer 5
• ✓Model answer 6
• ✓Model answer 7
• ✓Model answer 8
• ✓Model answer — Adapted from Edexcel IAL Chemistry Unit 1