Advanced Organic Synthesis & Purification Labs for H2 Chemistry Paper 4

Q: What does Advanced Organic Synthesis & Purification cover?
A: Step-by-step Paper 4 workflows for reflux, distillation, liquid–liquid extraction, recrystallisation, chromatography, and yield tracking-plus ACE commentary frameworks grounded in SEAB’s 2026 H2 Chemistry syllabus.

TL;DR
Organic tasks combine synthetic precision with safety discipline.
Control heating, phase separations, drying, and purity calculations so you can justify every observation and improvement during Paper 4.

Status: SEAB H2 Chemistry (9729, first exam 2026) syllabus last checked 2025-11-29 (PDF last modified 2024-07-17). Paper 4 remains 2 h 30 min, 55 marks, weighted at 20 % with Planning at 5 % and MMO/PDO/ACE at 15 % combined; simple organic synthesis and purification stay listed in the practical scope.

1 | Organic investigations in the 2026 syllabus

• The SEAB 2026 H2 Chemistry syllabus (9729) lists simple organic synthesis and purification in the Practical Assessment section (Paper 4: 2 h 30 min, 55 marks; Planning 5%, MMO/PDO/ACE 15%). Candidates must demonstrate safe manipulation, accurate observation, and evaluative commentary.
• Examiner reports often flag incomplete purification, poor yield documentation, and missing safety controls (e.g., reflux set-ups lacking clamps or open joints).
• The 9476 Paper 4 specimen for 2026 backs this up-Question 2 walks through an organic preparation, TLC confirmation, and yield discussion, echoing the reflux, extraction, and purification checkpoints summarised here.
• Common Paper 4 scenarios: esterification under reflux, nitration, oxidation/reduction, separation of product from by-products, determination of purity via melting point or TLC.

2 | Reflux & distillation mastery

• Apparatus: round-bottom flask, anti-bumping granules, Liebig or Allihn condenser (water in at bottom/out at top), heating mantle/hot plate, drying tube (when excluding moisture).
• Reflux steps: charge reagents, add anti-bumping granules, clamp securely, start coolant before heating, maintain gentle boil (liquid should return without climbing condenser).
• Distillation: switch to a still head with thermometer adapter and receiving adapter; monitor temperature plateau to identify fraction.
• Troubleshooting:
  • Bumping: add more anti-bumping granules or reduce heat.
  • Loss of volatile reagent: ensure condenser cold water flow is sufficient.