Chemistry - Organic Theory

Organic Chemistry

the study of carbon-containing compounds

Aliphatic

compounds that contain straight (or branched) chains

Aromatic

compounds that contain a benzene ring

Functional Group

group of atoms on which the characteristic properties of a particular compound depend

Homologous Series

group of compounds that contain the same functional group, have a general formula, show a graduation in physical properties, have similar properties but as you go up the series the successive members differ by CH2

Alkane

functional group is C-C

Alkene

functional group is C=C

Alkyne

functional group is C≡C

Alcohol

functional group is -OH

Ketone

functional group is C=O

Aldehyde

functional group is

Ester

functional group is

Carboxylic Acid

functional group is

Primary Alcohol

has one carbon attached to the carbon attached to the OH group

Secondary Alcohol

has two carbons attached to the carbon attached to the OH group

Tertiary Alcohol

has three carbons attached to the carbon attached to the OH group

Esters

are formed when a carboxylic acid reacts with an alcohol in the presence of dilute sulphuric acid

Sulphuric Acid

performs two tasks in esterification:

• acts as a catalyst

• soaks up the water formed

Condensation Reaction

where two molecules combine to form a larger molecule, with the loss of a small molecule, such as water

e.g. esterification

Making Soap

involves using fat (lard of vegetable oil) which contains naturally ocurring esters

Tetrahedral Carbons

are saturated

Planar Carbons

are unsaturated

Non Polar Solvents

ethyl benzene, benzene, and methyl benzene are examples

Benzene

a carcinogenic, aromatic compound

Benzaldehyde

found in almonds

Benzoic Acid

acts as a preservative

Benzene Bonds

are intermediate in length

Carbon in Benzene

is bonded to 2 other carbons and one hydrogen by sigma bonds

Sigma Bonds

bond carbons and hydrogen together in benzene

Electron in 2py Orbital

overlaps with neighbouring orbitals to form a ring above and below the main carbon ring in benzene

Delocalised Electrons

there are 6 in benzene, which give extra stability

Acidified Sodium Dichromate

used to oxidise alcohols, along with dilute sulphuric acid

Aldehydes

formed from the oxidation of primary alcohols

(same as carboxylic acids)

Carboxylic Acids

formed from the oxidation of primary alcohols

(same as aldehydes)

Ketones

formed by the oxidation of secondary alcohols

Aldehydes

are good reducing agents, ketones are not

Organic Compounds

burn to produce CO₂ and H₂O

Elimination Reaction

a double bond is formed and a small molecule is removed

Van der Waals

intermolecular force in alkanes, alkenes and alkynes

Dipole Dipole

intermolecular forces in aldehydes and ketones

Hydrogen

bonding in alcohols and carboxylic acids

Polymers

are made by joining smaller molecules into a long chain repeating structure

Polythene

use : plastic bags

Polypropene

use : lunch boxes

Polychloroethene

use : records

(aka PVC)

Polytetrafluoroethene

use : non stick coating on frying pans

(aka teflon)

Methanoic Acid

in ant and nettle stings

Carboxylic Acid

acts as an acid due to:

• inductive effect, C=O group pulls electrons away from the -OH group, allows H⁺ to be released

• stability of the carboxylate ions

Isomers

molecules with the same molecular formula but a different structural formula, due to different arrangement of atoms in space