Area of Study 1: How are organic compounds categorised and synthesised?

You will be able to:

• Explain why carbon can form such a wide range of organic compounds

• Draw and name key organic families using IUPAC rules (up to C₈)

• Compare physical properties of homologous series using structure and bonding

• Describe and write equations for important organic reactions

• Design simple multi-step reaction pathways for synthesising target molecules

• Explain how food molecules are broken down and built up in the body

• Calculate percentage yield and atom economy for reactions

• Evaluate the sustainability of manufacturing organic compounds using green chemistry ideas

1️⃣ Why Carbon Can Do So Much

Carbon is special because it can:

• Form four covalent bonds

• Make chains, rings, branched structures

• Form single, double, and triple bonds

• Bond strongly with elements like H, O, N, halogens

• Form structural isomers – same formula, different structure

2️⃣ Representing Organic Molecules

Students work with:

• Molecular formula – e.g. C₄H₁₀

• Structural formula – shows all bonds

• Semi-structural / condensed formula – CH₃CH₂CH₂OH

• Skeletal formula – lines and corners for carbon framework

Organic families covered (including cyclohexane and benzene):

• Alkanes (and cyclohexane)

• Alkenes

• Benzene

• Haloalkanes

• Primary amines

• Primary amides

• Alcohols (1°, 2°, 3°)

• Aldehydes

• Ketones

• Carboxylic acids

• Simple (non-branched) esters

3️⃣ Naming Organic Compounds – IUPAC Basics

Students name compounds up to C₈, with up to two functional groups, including:

• Non-cyclic hydrocarbons

• Haloalkanes

• Primary amines

• Alcohols (1°, 2°, 3°)

• Aldehydes & ketones

• Carboxylic acids

• Non-branched esters

Key naming skills:

1. Find the longest carbon chain

2. Number the chain to give lowest numbers to functional groups

3. Identify and name substituents (chloro-, methyl-, amino-, etc.)

4. Add correct suffix (–ol, –al, –one, –oic acid, –amine, –oate)

4️⃣ Physical Properties & Homologous Series

Students compare:

• Boiling and melting points

• Viscosity (thickness)

• Volatility (how easily they evaporate)

Using:

• Strength of intermolecular forces (dispersion, dipole–dipole, hydrogen bonding)

• Presence of functional groups

• Chain length and branching

5️⃣ Reactions of Organic Compounds & Pathways

Students learn key reaction types (with conditions):

🔁 Substitution

• Haloalkanes → alcohols

• Primary alcohols → haloalkanes

➕ Addition (Alkenes)

• Alkene + H₂ → alkane

• Alkene + halogen → dihaloalkane

• Alkene + H₂O → alcohol

🌸 Esterification

• Alcohol + carboxylic acid → ester + water

• Used to make flavourings and fragrances

💧 Hydrolysis of Esters

• Ester + water (or base) → alcohol + carboxylic acid (or salt)

🧬 Synthesis of Amines & Carboxylic Acids

• From haloalkanes, alcohols, or other precursors via multi-step reaction pathways.

🛢 Biodiesel – Transesterification

• Plant triglycerides (fats/oils) + alcohol → biodiesel + glycerol

🥗 Food Molecule Reactions

• Hydrolysis of:

  • Proteins → amino acids

  • Carbohydrates (starch) → sugars

  • Fats & oils → fatty acids + glycerol

• Condensation to build:

  • Proteins

  • Starch & glycogen

  • Lipids (fats & oils)

6️⃣ Yield and Atom Economy

• Percentage Yield

• Atom Economy

Higher atom economy means:

• Less waste

• More efficient use of reactants

• Better for the environment & industry

Conceptual Questions

1. Why can carbon form such a wide variety of compounds compared with other elements?

2. Explain why alcohols generally have higher boiling points than alkanes of similar molar mass.

3. Describe the difference between a condensation reaction and a hydrolysis reaction.

4. What is an ester and where might esters be used in everyday life?

5. Why is high atom economy important for both industry and the environment?

Calculation Questions

6. A reaction has a theoretical yield of 12.0 g, but only 8.7 g of product is obtained. Calculate the percentage yield.

7. In a reaction, total mass of reactants is 100 g, and the desired product has a mass of 60 g. Calculate the atom economy.

• Incorrect or incomplete IUPAC naming (wrong numbering or suffix)

• Confusing aldehydes and ketones (position of the C=O group)

• Forgetting that condensation removes a small molecule (usually water)

• Mixing up isomers vs different compounds entirely

• Ignoring green chemistry / sustainability in evaluation questions

• Make a functional group cheat sheet with name, structure, and example

• Practise naming and drawing at least 5 molecules daily

• Use model kits or drawing apps to explore isomers and pathways

• Memorise the key reaction types: substitution, addition, condensation, hydrolysis

• For long-answer questions, always mention structure, bonding AND sustainability where relevant