OCR A-Level Chemistry Unified chemistry (03), June 2018
Every question from OCR A-Level Chemistry Unified chemistry (03), June 2018 (H432): 6 questions, 70 marks, each with its mark scheme and topic.
- Question 1 13 marks
Identify specific elements from the first three periods based on physical and chemical properties, and explain the bonding and structure properties of Period 3 chlorides.
Module 2: Foundations in chemistry · Module 3: Periodic table and energy · 2.2 Electrons, bonding and structure · 3.1 The periodic table
- Question 2 13 marks
Investigate the decomposition of hydrogen peroxide, calculate initial concentration from gas volume, write redox equations using electrode potentials, and explain cobalt(II) complex equilibria and color changes.
Module 3: Periodic table and energy · Module 5: Physical chemistry and transition elements · Practical Activity Groups · 3.2 Physical chemistry · 5.1 Rates, equilibrium and pH · 5.2 Energy · 5.3 Transition elements · PAG 9: Rates of reaction – continuous monitoring method
- Question 3 10 marks
Draw 3D optical isomers for the iron(III) ethanedioate complex ion, state the colour change for a cerium(IV) redox titration, and calculate the percentage by mass of ethanedioic acid in rhubarb leaves.
Module 5: Physical chemistry and transition elements · Module 2: Foundations in chemistry · Practical Activity Groups · 5.3 Transition elements · 2.1 Atoms and reactions · PAG 2: Acid-base titration
- Question 4 11 marks
Determine the oxidation number of platinum in cis-platin, outline its mechanism of formation, identify functional groups in paracetamol, and calculate the mass of 4-nitrophenol required for a two-stage synthesis of paracetamol with a given percentage yield including purification details.
Module 5: Physical chemistry and transition elements · Module 6: Organic chemistry and analysis · Practical Activity Groups · 5.3 Transition elements · 6.1 Aromatic compounds, carbonyls and acids · 6.2 Nitrogen compounds, polymers and synthesis · PAG 6: Synthesis of an organic solid
- Question 5 11 marks
Calculate the enthalpy change of neutralisation and determine the equilibrium constant Kc for the esterification of succinic acid with ethanol.
Module 3: Periodic table and energy · Module 5: Physical chemistry and transition elements · Module 6: Organic chemistry and analysis · Practical Activity Groups · 3.2 Physical chemistry · 5.1 Rates, equilibrium and pH · 6.1 Aromatic compounds, carbonyls and acids · PAG 3: Enthalpy determination
- Question 6 12 marks
Name the product of the base-catalysed addition reaction of ethanal, write the mechanism/equations for its formation, draw the product for propanone reacting similarly, and explain the role of electrophiles with aliphatic and aromatic examples including mechanisms.
Module 4: Core organic chemistry · Module 6: Organic chemistry and analysis · 6.1 Aromatic compounds, carbonyls and acids · 4.1 Basic concepts and hydrocarbons