The Four Must-Master Topics

Based on exam data and official resources, these topics appear most frequently and carry the highest marks in IAL Chemistry Unit 1.

1. Formulae, Equations & Amount of Substance

According to past exam analysis, calculation questions make up 25-30% of the total marks¹.

Focus on:

• Mass, volume, and concentration calculations
• The ideal gas equation: PV = nRT
• Mass spectrometry process and applications
• Parts per million calculations

Quick Practice: Calculate the number of moles in 5.6g of iron. (Answer: 0.1 mol, using moles = mass ÷ molar mass)

2. Atomic Structure & Periodic Trends

This section typically accounts for 20-25% of exam questions².

Key areas:

• Electron configurations (1s², 2s², etc.)
• Periodic trends with reasons
• Atomic radius decreases across a period
• Ionisation energy increases across a period
• s, p, and d orbital shapes and electron filling

3. Bonding & Structure

This topic appears in roughly 25% of exam questions and connects to many other topics².

Learn:

• Metallic, ionic, and covalent bonding differences
• Dot-and-cross diagrams
• Molecular shapes and bond angles

4. Introductory Organic Chemistry

Organic chemistry makes up about 20% of Unit 1 but grows more important in later units³.

Focus on:

• Free radical substitution of alkanes
• Electrophilic addition to alkenes
• Testing for alkenes using bromine water
• Oxidation reactions of alkenes

Study Plan That Works

Data from student surveys shows that spaced repetition improves retention by up to 74%⁴.

1. Make flashcards for formulas and definitions
2. Practice 3-5 calculation problems daily
3. Draw mechanisms and structures regularly
4. Test yourself weekly on all topics

Exam Tips Based on Examiner Reports

• Show all calculation steps (worth 67% of marks even with wrong final answer)
• Include units in all answers
• Use correct arrow notation in mechanisms
• Link properties to structure when explaining

Resources You Can Trust

1. Pearson Edexcel IAL Chemistry Specification - Official exam requirements
2. Solved Past Paper - practice questions
3. Chem-Bio.info - Detailed explanations of complex topics

Bottom Line

Focus your study time on these four key areas. They make up over 90% of the exam and build the foundation for Units 2-6. Understanding why chemical processes happen will earn you more marks than just memorising facts.



Best of luck

Hosni