Organics 4.1

The International Union f Pure and Applied Chemistry, IUPAC, has developed a naming system for organic chemicals - the system of naming compounds is called nomenculture.

Families of organic chemiclas are called homologous series. To be members of a homologous series the substances must have the smae functional group and successive members differ onnly by a CH2 unit.

Aliphatic hydrocarbons - in which the carbon atoms are joined togther in either straight (unbranched) chains or branched chains.

Alicyclic hydrocarbons - in which the carbon satoms are joined togther in either straight (unbranched) chains or branched chains.

Aromatic hydrocarbons - in which there is at least one benzene ring in the structure.

Nomenculture is the naming system for compounds.

A homologous series is a series of organic compounds that have the same functional group with successive members differing by CH2.

Saturated compounds have only single bonds.

A functional group is a group of atoms that is responsible for the characteristic reactions of a compound.

All the compounds in an homologous series share the same general formula. This is the simplest algebraic formula for all the organic compouds in a homologous series and can be used to generate a molecular formula.

C<em>n</em>H2<em>n</em>+2’

CnH2<em>n</em>’

C<em>n</em>H2<em>n</em>+1OH

The relative positions of all the atoms in a molecule and the bonds between them. (In a displayed formula, it is important to show all the bonds, even those in functional groups. For example an alcohol group should be shown as -O-H not -OH.

A structual formual gives the minimum detail for the arrangement of atoms in a molecule. Butane would have the structual formula of CH3(CH2)2CH3.

• A general formula is the simplest alegbraic formula for a homologous series. • A structual formula provides the minimum detail for the arrangement of stoms in a nomlecule. • A displayed formula shows the relative positions of atoms and the bonds between them.

An empiricle formula shows the smallest whole-number ratio of atoms of the elements in a compound.

• Change the percentages to masses • Calculate the number of moles of each element using amount (moles) = mass (g) / relative atomic mass • Divide by the smallest value. • Change the ratio to whole numbers • Write the formula.

A molecular formula shows the numbers and types of atoms in a compound.

• Calculate the relative empiricle mass using the empircle formula. • Divide the realtive moleclar mass by the empiricle formula mass. • Multiply each atom in the empiricle formula by the number calculated in step 2 and write the molecular formula.

A skeletal formula is a simplified structual formula drawn by removing hydrogen atoms from alky chains.

Unsaturated organic chemicalscontain at leats one carbon-carbon double covalent bond.

Hydrocarbons are compounds that contain only hydrogen atoms and carbon atoms.

Saturated organic chemicals contain only single covalent bonds.