Chemistry

4. Organic Chemistry
4.1 Introduction>4.2 Crude Oil>4.3 Alkanes>4.4 Alkenes>4.5 Alcohols>4.6 Carboxylic Acids>4.7 Esters>4.8 Synthetic Polymers>

1. Principles of Chemistry

1.2 Elements, Compounds & Mixtures >1.3 Atomic Structure >1.4 The Periodic Table >1.5 Chemical Formulae, Equations and Calculations >1.6 Ionic Bonding >1.7 Covalent Bonding >1.8 Metallic Bonding >1.9 Electrolysis >

2. Inorganic Chemistry

2.1 Group 1 (Alkali Metals) – Lithium, Sodium and Potassium >2.2 Group 7 (Halogens) – Chlorine, Bromine and Iodine >2.3 Gases in the Atmosphere >2.4 Reactivity Series >2.5 Extraction and Uses of Metals >2.6 Acids, Alkalis and Titrations >2.7 Acids, Bases and Salt Preparations >2.8 Chemical Tests >

3. Physical Chemistry

3.1 Energetics >3.2 Rates of Reaction >3.3 Reversible Reactions and Equilibria >

4.1 Introduction

4.1.1 Know that a hydrocarbon is a compound of hydrogen and carbon only

Hydrocarbon is a compound containing hydrogen and carbon only.

4.1.2 Understand how to represent organic molecules using empirical formulae, molecular formulae, general formulae, structural formulae and displayed formulae

Empirical formula shows the simplest whole number ratio of atoms
Molecular formula shows the actual number of atoms
General formula shows a ratio of atoms in a family of compounds in terms of ‘n’ where n is a varying whole number
Simplified Structural formula shows the way in which atoms are bonded (Structure), but not all bonds
Displayed Structural formula shows all atoms and bonds in a molecule

4.1.3 Know what is meant by the terms homologous series, functional group and isomerism

HOMOLOGOUS SERIES

Series of compounds with:
- Same functional group
- Same general formula
- Similar chemical properties
- Gradually increasing physical properties along the series (e.g. boiling point)

FUNCTIONAL GROUP

A group of atoms present in the compound
It is a distinctive combination of atoms in the compound
It is responsible for the chemical reactions of a compound

ISOMERISM

Compounds with:
- Same molecular formula
- But different structural formula
- Due to different arrangements of atoms

More will be discussed throughout this topic.

4.1.4 Understand how to name compounds relevant to this specification using the rules of international Union of Pure and Applied Chemistry (IUPAC) nomenclature students will be expected to name compounds containing up to six carbon atoms

PREFIXES (BEGINNING OF THE NAME)

Depends on the number of carbons in the parent chain – parent chain is the longest continuous carbon chain
1C – Meth
2C – Eth
3C – Prop
4C – But
5C – Pent
6C – Hex

SUFFIXES

Refers to the functional group
Alkanes – ane
Alkenes – ene
Alcohol – ol
Carboxylic acids – anoic acid
Esters – yl, anoate

4.1.5 Understand how to write the possible structural and displayed formulae of an organic molecule given its molecular formula

If the molecular formula given is C₂H₆:

Structural formula: CH₃CH₃
Displayed formula:

Be aware of isomers

Different structural formula and displayed formula can be drawn from same molecular formula

Example: C₅H₁₂

To name the alkane isomers:

Consider the number of carbons in the longest continuous carbon chain.

Know that the CH3 group is called the “methyl” group .

4.1.6 understand how to classify reactions of organic compounds as substitution, addition and combustion

Knowledge of reaction mechanisms is not required

ADDITION REACTIONS

Involve only one product
2 reactants → 1 product
E.g. ethene + hydrogen → ethane

SUBSTITUTION REACTIONS

Involve two products
2 reactants → 2 products
Hydrogen chloride + ethanol → chloroethane + water
(Cl replaces OH, they swap places)

COMBUSTION REACTIONS

Involves the reaction of a fuel with oxygen
Complete combustion of hydrocarbon produces water and carbon dioxide
Incomplete combustion of hydrocarbon produces water and carbon monoxide