organic chemistry

homologous series

A family of organic compounds with the same functional group and similar chemical properties, where successive members differ by CH₂.

functional group

The part of a molecule responsible for its characteristic chemical reactions.

addition reaction

A reaction in which atoms are added to a molecule without the loss of any atoms

substitution reaction

A reaction in which one atom or group is replaced by another.

elimination reaction

A reaction in which a small molecule is removed, forming a double bond.

alkanes

• all single bonds

• -ane

alkenes

• double bonds between the carbons

• -ene

alcohols

• hydroxyl group C-OH

• -ol

• OH attatched to carbon

aldehydes

• carbonyl: C=O bonded to H at the end of the chain

• al

ketones

• carbonyl C=O in the middle of the molecule

• -one

• C=O is stuck between two carbons

carboxylic acids

• carbonyl is attached to hydroxyl (OH)

• -oic acid

• COOH group at the end one the same carbon

Esters

• carbonyl attatched to the O in the middle of the molecule

• - -COO-

• -yl oate

• C=O is attatched to another chain

addition reactions

2 molecules combine to form a larger molecule

alkenes → alkanes

ionic radiation

mechanisms of addition

1) Polarisation

2) Heterolytic fission

3) Carbonium ion

4) Ionic addition

Substitution reactions

A substition reaction is a chemical reaction in which an atom or group of atoms in a molecule is replaced by another atom or group of atoms.

• alkanes (commonely)

• esters

needs UV light

substition: halogenation of alkanes

• alkanes react with halogens → a hydrogen atom in the alkane is replaced by a halogen atom

• halogenation: typically under UV light

free radical

an atom/ molecule/ group of atoms that contain an unpaired electron

mechanism of free radical substitution

• initiation

• propagation

• termination

homolytic fission

each atom joined by the covalent bond keeps one of the two electrons in the bond.

initiation

• UV light provides the energy needed to break the chlorine molecule by homolytic fission producing two chlorine radicals, each containing an unpaired electron.

propogation

• a chlorine radical reacts with methane, removing one hydrogen and creating a methyl radical and hydrogen chloride

• the methyl radical then reacts with another chlorine molecule forming chloromethane and creating another chlorine radical which continues the chain reaction

terination

• chain reaction ends when two radicals combine to form a stable molecule stopping the reactions

evidence for the free radical mechanism

• use of ultraviolet light - the reaction does not proceed without UV light (necessary to break the Cl2 and produce radicals

• chain reaction

• formation of ethane and utane

• radica promotors

chain reactions

a reaction that continues on an on because a product from one step is a reactant in another

Esterification

he process by which a carboxylic acid reacts with an alcohol to form an ester and water. This reaction is typically catalysed by an acid, such as sulfuric acid (H2​SO4​).

Base Hydrlysis

The breakdown of esters (fats) into alcohols (glycerol) and salts of fatty acids (soap).

Soap manufacture

The production of soap involves the base hydrolysis (saponification) of natural fats and oils, which are triglycerides (esters of fatty acids and glycerol).

• In the presence of sodium hydroxide (NaOH), triglycerides (fats) are broken down into glycerol and the sodium salts of fatty acids, which are the soap molecules.

• Reactants: Triglycerides consist of a glycerol backbone attached to three fatty acid chains.

• Products: The fatty acid chains (now in the form of sodium salts) are the soap molecules, and glycerol is a byproduct.

Elimination Reactions

here atoms or groups of atoms are removed from a molecule, resulting in the formation of a double or triple bond.

• opposite of addition reactions

• alcohols/ chloroalkanes → alkenes

• forms a double bond

Redox reactions

• the transfer of electrons between substances, resulting in oxidation (loss of electrons) and reduction (gain of electrons)

• transformation of alcohols, aldehydes, and ketones.

• Oxidation alcohols → carboxylic acids