Organic Chemistry for Matric: Complete IUPAC Naming and Reactions Guide
Complete guide to Matric Organic Chemistry covering all functional groups, IUPAC naming rules, key reactions, and polymer chemistry as tested in NSC Physical Sciences Paper 2.
By Tania Galant in Subject Guides · 8 min read
Key Takeaways
There are 10 functional groups you must know for Matric including naming, structure, and properties
IUPAC naming follows a systematic set of rules that become easy with practice
Five key reaction types are tested: substitution, elimination, addition, esterification, and combustion
Polymer questions are almost guaranteed and follow predictable patterns
# Organic Chemistry for Matric: Complete IUPAC Naming and Reactions Guide
Organic Chemistry is one of the most content-heavy topics in Matric Physical Sciences, but it is also one of the most rewarding. It appears in Paper 2 and is worth approximately 30-35 marks. Unlike some physics topics where you might get stuck on a calculation, organic chemistry rewards learners who put in the effort to learn the content systematically.
This guide covers every functional group, the IUPAC naming system, all the reactions you need to know, and the polymer chemistry that appears in nearly every NSC exam. For the full Physical Sciences study plan, see our [physical sciences guide](/blog/matric-physical-sciences-past-papers-and-exam-guide-your-complete-study-companion).
## The Functional Groups You Must Know
> **Read more:** For a comprehensive overview, see our [physical sciences exam guide](/blog/matric-physical-sciences-past-papers--exam-guide).
A functional group is the specific group of atoms within a molecule that determines the molecule's chemical properties. The CAPS curriculum requires you to know these ten:
| Functional Group | General Formula | Suffix/Prefix | Example |
|---|---|---|---|
| Alkane | CnH2n+2 | -ane | Propane (CH3CH2CH3) |
| Alkene | CnH2n | -ene | But-2-ene (CH3CH=CHCH3) |
| Alkyne | CnH2n-2 | -yne | Eth-1-yne (CH≡CH) |
| Alcohol | R-OH | -ol | Propan-1-ol (CH3CH2CH2OH) |
| Carboxylic acid | R-COOH | -oic acid | Ethanoic acid (CH3COOH) |
| Ester | R-COO-R' | -oate | Methyl ethanoate (CH3COOCH3) |
| Aldehyde | R-CHO | -al | Propanal (CH3CH2CHO) |
| Ketone | R-CO-R' | -one | Propanone (CH3COCH3) |
| Amine | R-NH2 | -amine / amino- | Ethylamine (CH3CH2NH2) |
| Amide | R-CONH2 | -amide | Ethanamide (CH3CONH2) |
### Recognising Functional Groups
In the exam, you will often be given a structural formula and asked to identify the functional group. Look for:
- **Double bond between carbons** means Alkene
- **Triple bond between carbons** means Alkyne
- **-OH group** means Alcohol (unless attached to a C=O, then it is a carboxylic acid)
- **-COOH group** means Carboxylic acid
- **-COO- group** (C=O with an O linking to another carbon chain) means Ester
- **-CHO group** (C=O at the end of the chain) means Aldehyde
- **-CO- group** (C=O in the middle of the chain) means Ketone
- **-NH2 group** means Amine
- **-CONH2 group** means Amide
## IUPAC Naming Rules
IUPAC (International Union of Pure and Applied Chemistry) naming follows a systematic method. Here is the step-by-step process:
### Step 1: Find the Longest Carbon Chain
Count the longest continuous chain of carbon atoms that includes the functional group. This gives you the parent name:
| Carbons | Parent Name |
|---|---|
| 1 | Meth- |
| 2 | Eth- |
| 3 | Prop- |
| 4 | But- |
| 5 | Pent- |
| 6 | Hex- |
| 7 | Hept- |
| 8 | Oct- |
### Step 2: Number the Carbon Chain
Number from the end that gives the functional group the lowest possible number. If there is no functional group (alkane), number from the end that gives substituents the lowest numbers.
### Step 3: Identify and Name Substituents
Substituents (branches) are named as prefixes:
- -CH3 is methyl
- -CH2CH3 is ethyl
- -Cl is chloro
- -Br is bromo
If there are multiple identical substituents, use di- (2), tri- (3), tetra- (4).
### Step 4: Put It All Together
The name format is: [substituent position]-[substituent name][parent chain name][suffix]
**Examples:**
- CH3CH2CH2OH is **Propan-1-ol** (3-carbon chain, OH on carbon 1)
- CH3CHClCH2CH3 is **2-Chlorobutane** (4-carbon chain, Cl on carbon 2)
- CH3CH=CHCH3 is **But-2-ene** (4-carbon chain, double bond starting at carbon 2)
- CH3CH2COOH is **Propanoic acid** (3-carbon chain including the COOH carbon)
### Naming Esters
Esters have a special naming pattern: [alkyl group from alcohol] [carboxylic acid stem]-oate
Example: The ester formed from ethanoic acid and methanol is **methyl ethanoate**.
### Common Naming Mistakes
1. **Not finding the longest chain.** Make sure the chain you choose is actually the longest and includes the functional group.
2. **Numbering from the wrong end.** The functional group gets the lowest number.
3. **Forgetting position numbers.** For chains with 3+ carbons, you must indicate the position of the functional group (propan-1-ol, not just propanol).
4. **Incorrect ester naming.** Remember: the alcohol part comes first in the name.
## Key Reactions
### 1. Combustion Reactions
All organic compounds undergo combustion (burning in oxygen):
**Complete combustion:** Organic compound + O2 → CO2 + H2O
This applies to all hydrocarbons and is straightforward to balance.
### 2. Substitution Reactions
A substitution reaction is one where an atom or group of atoms is replaced by another atom or group of atoms.
**Key example — Halogenation of alkanes:**
- CH4 + Cl2 → CH3Cl + HCl (in the presence of UV light)
- One hydrogen is replaced by a chlorine atom.
- Conditions: UV light or high temperature.
**Key example — Hydrolysis of haloalkanes:**
- CH3CH2Br + NaOH → CH3CH2OH + NaBr
- The halogen is replaced by an -OH group.
- Conditions: Warm NaOH solution.
### 3. Elimination Reactions
An elimination reaction involves the removal of atoms from adjacent carbon atoms to form a double bond.
**Key example — Dehydration of alcohols:**
- CH3CH2OH → CH2=CH2 + H2O
- An -H and -OH are removed from adjacent carbons.
- Conditions: Concentrated H2SO4 (or H3PO4) at high temperature, or Al2O3 at high temperature.
**Key example — Dehydrohalogenation:**
- CH3CH2Br + NaOH (in ethanol) → CH2=CH2 + NaBr + H2O
- Conditions: Hot concentrated NaOH in ethanol.
**Important:** The same reactants (haloalkane + NaOH) can give different products depending on conditions:
- NaOH in water → substitution (forms alcohol)
- NaOH in ethanol → elimination (forms alkene)
### 4. Addition Reactions
Addition reactions occur when atoms are added across a double bond (alkenes only).
**Key examples:**
- **Hydrogenation:** CH2=CH2 + H2 → CH3CH3 (using Pt/Pd/Ni catalyst)
- **Halogenation:** CH2=CH2 + Br2 → CH2BrCH2Br
- **Hydrohalogenation:** CH2=CH2 + HBr → CH3CH2Br
- **Hydration:** CH2=CH2 + H2O → CH3CH2OH (using H2SO4 catalyst)
**Note:** Bromine water is used as a test for unsaturation (double bonds). If the brown bromine water decolourises, a double bond is present.
### 5. Esterification and Hydrolysis
**Esterification:** Carboxylic acid + Alcohol → Ester + Water
- CH3COOH + CH3OH ⇌ CH3COOCH3 + H2O
- Conditions: Concentrated H2SO4 catalyst, heat.
- This is a reversible reaction.
**Hydrolysis of esters:** Ester + Water → Carboxylic acid + Alcohol
- This is the reverse of esterification.
- Acid hydrolysis: Use dilute HCl or H2SO4.
- Base hydrolysis (saponification): Use NaOH.
## Summary of Reactions
| Reaction Type | Starting Material | Product | Conditions |
|---|---|---|---|
| Substitution (halogenation) | Alkane + X2 | Haloalkane + HX | UV light |
| Substitution (hydrolysis) | Haloalkane + NaOH | Alcohol + NaX | NaOH in water, warm |
| Elimination (dehydration) | Alcohol | Alkene + H2O | Conc. H2SO4, heat |
| Elimination (dehydrohalogenation) | Haloalkane + NaOH | Alkene + NaX + H2O | NaOH in ethanol, heat |
| Addition (hydrogenation) | Alkene + H2 | Alkane | Pt/Pd/Ni catalyst |
| Addition (halogenation) | Alkene + X2 | Dihaloalkane | Room temperature |
| Addition (hydration) | Alkene + H2O | Alcohol | H2SO4 catalyst |
| Esterification | Acid + Alcohol | Ester + H2O | Conc. H2SO4, heat |
## Polymers
Polymer questions appear in nearly every NSC exam. There are two types:
### Addition Polymers
- Formed from monomers with double bonds (alkenes).
- The double bond opens up and monomers link together.
- No by-product is formed.
- Example: Polyethylene (from ethene), polypropylene (from propene), PVC (from chloroethene).
**Identifying addition polymers:** Look for a repeating unit with a backbone of only carbon atoms and no atoms lost between monomers.
### Condensation Polymers
- Formed from monomers with two functional groups each.
- A small molecule (usually water) is released with each link.
- Examples: Polyesters (from diacids + diols), polyamides (from diacids + diamines).
**Identifying condensation polymers:** Look for ester linkages (-COO-) or amide linkages (-CONH-) in the polymer chain.
### Exam Questions on Polymers
Common questions include:
- Identifying the monomer(s) from a given polymer structure.
- Drawing the repeating unit of a polymer.
- Identifying whether a polymer is addition or condensation.
- Naming the type of polymerisation.
## Exam Approach Tips
1. **Learn functional groups first.** If you cannot recognise and name functional groups, nothing else in organic chemistry makes sense.
2. **Practise naming systematically.** Work through 20-30 naming exercises until the method is automatic.
3. **Make reaction summary sheets.** Create your own summary table of reactions with reactants, products, and conditions.
4. **Conditions matter.** Many marks are lost by forgetting to state the catalyst or conditions for a reaction.
5. **Practise drawing structural formulae.** The exam often requires you to draw molecules — make sure your bonds and atoms are clear.
Download past papers from our [past papers page](/past-papers) and use our [past papers guide](/blog/the-complete-guide-to-matric-past-papers-everything-you-need-to-know) to practise organic chemistry questions.
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## Related Resources
- [Matric Physical Sciences Past Papers & Exam Guide: Your Complete Study Companion](/blog/matric-physical-sciences-past-papers-exam-guide-your-complete-study-companion)
- [Browse All Matric Past Papers](/past-papers)
- [Exam Preparation Guide](/exam-preparation)
- [Matric Mathematics Paper 1 vs Paper 2: Key Differences and How to Prepare for Each](/blog/matric-mathematics-paper-1-vs-paper-2-key-differences-and-how-to-prepare-for-each)
- [Euclidean Geometry Proofs: A Complete Guide for Matric Mathematics](/blog/euclidean-geometry-proofs-a-complete-guide-for-matric-mathematics)
- [Newton's Laws Made Simple: Matric Physical Sciences Paper 1 Guide](/blog/newtons-laws-made-simple-matric-physical-sciences-paper-1-guide)
- [Start Practising Free on LearningLoop](/auth?tab=register)
## Frequently Asked Questions
### How many marks is Organic Chemistry worth in Paper 2?
Organic Chemistry is typically worth 30-35 marks in Paper 2, making it one of the highest-weighted topics.
### Do I need to memorise all the functional groups?
Yes. You need to recognise, name, and draw structural formulae for all ten functional groups listed in the CAPS curriculum.
### What is the difference between substitution and elimination?
In substitution, an atom or group is replaced by another. In elimination, atoms are removed to form a double bond. The same reactants can undergo either reaction depending on conditions.
### How do I know if a polymer is addition or condensation?
Look at the backbone: if it is all carbon atoms with no linkage groups, it is addition. If there are ester (-COO-) or amide (-CONH-) linkages, it is condensation.
### Do I need to memorise reaction conditions?
Yes. Conditions (catalysts, temperature, solvents) are frequently tested and carry marks.
### What is the most common mistake in IUPAC naming?
Numbering the chain from the wrong end, resulting in the functional group getting a higher number than necessary.
### Can I use molecular formulae in the exam?
For naming questions, you need to use structural or condensed structural formulae. Molecular formulae alone are usually not sufficient for full marks.
### How should I revise Organic Chemistry?
Start with functional groups, then naming, then reactions. Use flashcards for functional groups and a summary table for reactions. Practise with past papers to see how questions are structured.
Explore more [Physical Sciences past papers](/subjects/physical-sciences) on our [subjects page](/subjects).