EJC 2024 H2 Chemistry Planning Worked Examples and Practice Questions Booklet

W O R K E D E X A M P L E S A N D P R A C T I C E Q U E S T I O N S P a g e | 2 Contents 1 Volumetric Analysis ................................ ................................ ................................ ................. 4 1.1 Acid-Base Titrations ................................ ................................ ................................ ......... 5 Worked Example 1A: Direct Titration ................................ ................................ ......................... 5 Worked Example 1B: Back Titration ................................ ................................ ........................... 7 1.2 Redox Titrations ................................ ................................ ................................ ................ 9 Worked Example 1C: Redox Titration Involving MnO4 (MJC 2018/4/1e) ................................ ... 9 Practice Question 1A: Redox Titration Involving Autocatalytic Reaction (NYJC 2018/4/1g) ..... 12 Practice Question 1B: Redox Titration Involving I2 and S2O32− (JJC 2018/4/3) ......................... 13 2 Gravimetric Analysis ................................ ................................ ................................ ............. 15 Worked Example 2A: Volatilisation Gravimetry (9259 2008) ................................ .................... 16 Practice Question 2A: Volatilisation Gravimetry Involving CuSO4·nH2O ................................ ... 18 Practice Question 2B: Volatilisation Gravimetry Involving Carbonates (SAJC 2018/4/1g) ........ 18 Practice Question 2C: Precipitation Gravimetry (ACJC 2019/4/1g) ................................ .......... 19 3 Gas Collection Experiments................................ ................................ ................................ .. 20 Worked Example 3A (DHS 2018/4/2a) ................................ ................................ ..................... 21 Practice Question 3A (TJC 2018/4/1c) ................................ ................................ ..................... 24 4 Chemical Energetics ................................ ................................ ................................ .............. 25 4.1 Calorimetry ................................ ................................ ................................ ...................... 26 Worked Example 4A: Finding Enthalpy Change of Solution ................................ ..................... 28 Worked Example 4B: Finding Enthalpy Change of Combustion ................................ ............... 31 Practice Question 4A (CJC 2018/4/2) ................................ ................................ ...................... 34 Practice Question 4B (HCI 2018/4/3) ................................ ................................ ....................... 34 4.2 Thermometric Titrations ................................ ................................ ................................ . 36 Worked Example 4C (CJC 2019/4/3) ................................ ................................ ....................... 37 Worked Example 4D (NYJC 2018/4/1h) ................................ ................................ ................... 40 Practice Question 4C (PJC 2018/4/1g – modified) ................................ ................................ ... 43 5 Reaction Kinetics ................................ ................................ ................................ ................... 44 5.1 Overview of a Kinetic Study ................................ ................................ ........................... 45 5.2 Discontinuous Method ................................ ................................ ................................ ... 46 Worked Example 5A: Discontinuous Method (Deduction via Initial Rate Method) .................... 47 Worked Example 5B: Discontinuous Method (Deduction via Graphical Method) ...................... 49 Practice Question 5A: Discontinuous Method (EJC 2018/4/3b) ................................ ................ 51 Practice Question 5B: Discontinuous Method (Changing Temperature) (IJC 2018/4/2f–g) ....... 51 5.3 Continuous Method ................................ ................................ ................................ ........ 52 Worked Example 5C: Sampling Method (Deduction via Graphical Method) ............................. 54 Practice Question 5C: Continuous Method (modified 2017 A level P4/2c) ............................... 56 6 Qualitative Analysis ................................ ................................ ................................ ............... 57 6.1 Inorganic Qualitative Analysis ................................ ................................ ....................... 57

E S S E N T I A L S O F P L A N N I N G E X P E R I M E N T S 3 | P a g e Worked Example 6A ................................ ................................ ................................ ................ 59 Worked Example 6B ................................ ................................ ................................ ................ 60 Practice Question 6A: Inorganic QA (PJC 2018/4/3d) ................................ .............................. 61 Practice Question 6B: Inorganic QA (TJC 2018/4/3e) ................................ .............................. 61 6.2 Organic Qualitative Analysis ................................ ................................ .......................... 62 Worked Example 6C ................................ ................................ ................................ ................ 64 Worked Example 6D (HCI 2018/4/4d) ................................ ................................ ...................... 65 Worked Example 6E: Inorganic and Organic QA (RI 2018/4/3c) ................................ .............. 66 Practice Question 6C: Organic QA (RI 2017/4/3b) ................................ ................................ ... 67 Practice Question 6D: Organic QA (NYJC 2017/4/3i) ................................ ............................... 67 7 Organic Synthesis ................................ ................................ ................................ ................. 69 7.1 Synthesis ................................ ................................ ................................ ......................... 69 7.2 Isolation ................................ ................................ ................................ ........................... 71 7.3 Purification ................................ ................................ ................................ ...................... 74 7.4 Characterisation ................................ ................................ ................................ .............. 76 Worked Example 7A (Nov 2010/2/2) ................................ ................................ ........................ 78 Worked Example 7B (Nov 2011/2/1) ................................ ................................ ........................ 81 Practice Question 7A ................................ ................................ ................................ ............... 85 Practice Question 7B (AJC 2018/4/3c) ................................ ................................ ..................... 86 Suggested Solutions to Practice Questions ................................ ................................ ............... 88 Practice Question 1A: Redox Titration Involving Autocatalytic Reaction (NYJC 2018/4/1g) ..... 88 Practice Question 1B: Redox Titration Involving I2 and S2O32− (JJC 2018/4/3) ......................... 88 Practice Question 2A: Volatilisation Gravimetry Involving CuSO4·nH2O ................................ ... 90 Practice Question 2B: Volatilisation Gravimetry Involving Carbonates (SAJC 2018/4/1g) ........ 90 Practice Question 2C: Precipitation Gravimetry (ACJC 2019/4/1g) ................................ ........