OCR A-Level Chemistry Unified chemistry (03), November 2020
Every question from OCR A-Level Chemistry Unified chemistry (03), November 2020 (H432): 6 questions, 70 marks, each with its mark scheme and topic.
- Question 1 16 marks
Complete organic preparation diagrams, explain amine boiling points, determine the molecular formula and structure of an amine using ideal gas calculations and NMR data, and complete an organic reaction equation.
Module 6: Organic chemistry and analysis · Practical Activity Groups · PAG 5: Synthesis of an organic liquid · 6.2 Nitrogen compounds, polymers and synthesis · 6.3 Analysis
- Question 2 6 marks
Explain the terms ligand, coordination number and ligand substitution using examples of complex ions with different shapes, limited to monodentate ligands.
Module 5: Physical chemistry and transition elements · 5.3 Transition elements
- Question 3 10 marks
Determine the enthalpy change of combustion of propane using experimental calorimetry data and bond enthalpies accounting for vaporisation.
Module 3: Periodic table and energy · Practical Activity Groups · PAG 3: Enthalpy determination · 3.2 Physical chemistry
- Question 4 19 marks
Analyze an investigation determining the identity of metal M using a back-titration and metal X in a carbonate using mass loss during a reaction with hydrochloric acid.
Module 1: Development of practical skills in chemistry · Module 2: Foundations in chemistry · Practical Activity Groups · Module 6: Organic chemistry and analysis · PAG 2: Acid-base titration · 6.3 Analysis · 2.1 Atoms and reactions · 1.1 Practical skills assessed in a written examination
- Question 5 9 marks
Calculate enthalpy change and entropy change for an equilibrium using van 't Hoff equation data, a graph of ln Kp against 1/T, and the effect of temperature on equilibrium position.
Module 5: Physical chemistry and transition elements · 5.1 Rates, equilibrium and pH · 5.2 Energy
- Question 6 10 marks
Predict bond angles and shapes, explain acid strength using pKa values, and draw a reaction mechanism involving curly arrows for carboxylic and sulfonic acids and their derivatives.
Module 2: Foundations in chemistry · Module 5: Physical chemistry and transition elements · Module 6: Organic chemistry and analysis · 5.1 Rates, equilibrium and pH · 2.2 Electrons, bonding and structure · 6.1 Aromatic compounds, carbonyls and acids