18.1 to 18.3 Organic Chemistry

Alkenes

are unsaturated hydrocarbons with carbon- carbon double bonds (C= C)

chain length

As carbon increases the colour of the liquid gets darker as it gets thicker and more viscous.

Kerosene

and diesel oil are often cracked to produce petrol, other alkenes and hydrogen.

similar properties

The molecules in each fraction have and boiling points, which depend on the number of carbon atoms in the chain.

lubricants

Lubricating oil: for , polishes, waxes.

Fractional distillation

is carried out in a fractionating column.

Alkanes

are a group of saturated hydrocarbons.

Gradation

in their physical properties, such as melting and boiling point.

Naphtha

: raw product for producing chemicals.

black liquid

It is a thick, sticky, that is found under porous rock (under the ground and under the sea)

Volatility

refers to the tendency of a substance to vaporise.

Hydrogen

and a higher proportion of alkenes are formed at higher temperatures and higher pressure.

Hydrocarbons

are made from hydrogen and carbon atoms only.

smaller alkanes

The molecules are broken up in a random way which produces a mixture of and alkenes.

chemical properties

This is a series or family of organic compounds that have similar features and due to them having the same functional group.

Petroleum

is also called crude oil and is a complex mixture of hydrocarbons which also contains natural gas.

natural gas

Most common fossil fuels include coal, and hydrocarbons such as methane and propane which are obtained from crude oil.

Structural isomers

are compounds that have the same molecular formula but different structural formulae.

fuel

A(n) is a substance which when burned, releases heat energy.

Organic chemistry

is the chemistry of carbon compounds.

C C

The presence of the double bond, , means they can make more bonds with other atoms by opening up the bond and allowing incoming atoms to form another single bond with each carbon atom of the functional group.

names of organic compounds

The have two parts: the prefix (or stem) and the end part (or suffix)

Methane

is an alkane and is the major component of natural gas.

Organic compounds

can be represented in a number of ways.

High viscosity liquids

are thick and flow less easily.

catalytic cracking

A process called is used to convert longer- chain molecules into short- chain and more useful hydrocarbons.

colourless compounds

They are which have a gradual change in their physical properties as the number of carbon atoms in the chain increases.

molecular mass

The liquid flows less easily with increasing .

Organic molecules

are classified by the dominant functional group on the molecule.

homologous series

The functional group is a group of atoms which are bonded in a specific arrangement that is responsible for the characteristic reactions of each member of a(n) .

Kerosene

: for making jet fuel (paraffin)

fractional distillation

The fractions in petroleum are separated from each other in a process called .

Petroleum

itself as a mixture isn't very useful but each component part of the mixture, called a fraction, is useful and each fraction has different applications.

Alkanes

are generally unreactive compounds but they do undergo combustion reactions, can be cracked into smaller molecules and can react with halogens in the presence of light.

Alkenes

can be used to make polymers and the hydrogen used to make ammonia.

1

General Formula

2

Displayed Formula

The names of organic compounds have two parts

the prefix (or stem) and the end part (or suffix)

Cracking involves heating the hydrocarbon molecules to around 600

700°C to vaporise them

Refinery gas

heating and cooking

Gasoline

fuel for cars (petrol)

Naphtha

raw product for producing chemicals

Kerosene

for making jet fuel (paraffin)

Diesel

fuel for diesel engines (gas oil)

Fuel oil

fuel for ships and for home heating

Lubricating oil

for lubricants, polishes, waxes

Bitumen

for surfacing roads

There are two types

 chain and position