Chemistry Unit 2 F322 OCR AS Revision Notes

AS CHEMISTRY UNIT 2: F322

UNIT 2 Chains, Energy and Resources revision guide

Module 1: Basic Concepts and Hydrocarbons

·       2.1.1          Basic Concepts

·       2.1.2           Alkanes

·       2.1.3          Alkenes

Module 2: Alcohols, Halogenoalkanes and Analysis

·       2.2.1          Alcohols

·       2.2.2          Halogenoalkanes

·       2.2.3          Modern Analytical Techniques

Module 3: Energy

·       2.3.1           Enthalpy Changes

·       2.3.2          Rates and Equilibrium

Module 4: Resources

·       2.4.1          Chemistry of the Air

·       2.4.2           Green Chemistry

 

Module 1

 

2.1.1 Basic Concepts

Formulae of Organic Compounds

Terms

-        Empirical Formula: The simplest whole-number ratio of atoms of each element present in a compound.

-        Molecular Formula: The number of atoms of each element in a molecule, e.g. propane C₃H₈.

-        General Formula: The simplest algebraic formula of a member of a homologous series. For example, the general formula of the alkanes is C_nH_2n+2.

-        Structural Formula: A formula showing the minimal detail for the arrangement of atoms in a molecule, e.g. for butane: CH₃CH₂CH₂CH₃ or CH₃(CH₂)₂CH_3.

-        Displayed Formula: A formula showing the relative positioning of all the atoms in a molecule and the bonds between them, e.g. pentane

-        Skeletal Formula: A simplified organic formula, with hydrogen atoms removed from alkyl chains, leaving just a carbon skeleton and associated functional groups,

e.g. butan-2-ol

NOTE

-        In structural formulae, the carboxyl group will be represented as COOH and the ester group as COOR

-        Benzene can be represented like thisor like this

 

 

 

 

 

 

 

 

 

 

 

 

Functional groups and the naming of organic compounds

Terms

-        Homologous series: A series of organic compounds with the same functional group, but with each successive member differing by CH_2.

-        Functional group: The part of the organic molecule responsible for its chemical reactions.

 

Need to know first 10 members of the alkanes homologous series:

Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane, Decane.

 

Functional Groups

Type of Compound

Formula

Prefix

Suffix

Alkane

C-C

 

-ane

Alkene

C=C

 

-ene

Halogenoalkane

-F

-Cl

-Br

-I

Fluoro-

Chloro-

Bromo-

Iodo-

 

Alcohol

-OH

Hydroxy-

-ol

Aldehyde

-CHO

 

-al

Ketone

C-CO-C

 

-one

Carboxylic Acid

-COOH

 

-oic acid

 

NOTE

In names:

·         Di- is added to show two identical groups

·         Tri- is added to show three identical groups

·         Tetra- is added to show four identical groups

When naming substances, always put where the functional group is on the carbon chain.

e.g. this would be named butan-2-ol

Isomerism

Terms

-        Structural isomers: Molecules with the same molecular formula but…