Chemistry -- Organic ALL

Cracking of hydrocarbons

Breaking apart long hydrocarbons into shorter more useful hydrocarbons

Catalytic cracking

Vaporise hydrocarbon and pass gas over a hot powered aluminium oxide catalyst

Steam cracking

Vaporise hydrocarbon, mix with steam, heat to a very high temperature

Reactant in cracking

Long alkane molecules

Products of cracking

Shorter chain alkanes and alkenes

Test for alkenes

Turn bromine water orange to colourless

Long alkanes are not useful

As they are not very flammable

Shorter chain alkanes are more useful

As they are more flammable

Uses of alkenes

Making polymers and making other chemicals

Reactivity of alkenes

More reactive than alkanes

Ethene

C2H4

propene

C3H6

Butene

C4H8

Homologous series

A series of organic compounds with the same functional group but with each successive compound differing by CH2

Alkane

a hydrocarbon containing only single covalent bonds

General formula of alkanes

CnH2n+2

Alkene

A hydrocarbon that contains a double bond.

double covalent bond

a bond in which two atoms share two pairs of electrons

General formula of alkenes

CnH2n

Alkenes suffix

-ene

Alkanes suffix

-ane

Meth- prefix

1 carbon

Eth- prefix

2 carbons

Prop- prefix

3 carbons

But- prefix

4 carbons

Molecular formula

A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

Display formula

Shows all of the atoms in the molecule and their arrangements

saturated hydrocarbon

A hydrocarbon in which all the bonds between carbon atoms are single bonds

Hydrocarbons - Trend in boiling point

The longer the hydrocarbon, the higher its boiling point

Hydrocarbons - Trend in viscosity

The longer the hydrocarbon, the more viscous it is

Hydrocarbons - Trend in flammability

The shorter the hydrocarbon, the more flammable it is

Complete combustion

A combustion reaction in the presence of plenty of oxygen, producing carbon dioxide and water

Incomplete combustion

Combustion with insufficient oxygen, producing water, carbon particulates and carbon monoxide.

Crude oil

A finite fossil fuel made from buried plankton which has decomposed under mud for millions of years

Crude oil isn't useful because

It is a mixture of lots of hydrocarbons of a huge range of lengths

Composition of crude oil

Mainly hydrocarbons, with a few impurities such as sulfur

Hydrocarbon

A substance which is only made of hydrogen and carbon

Fractional distillation of crude oil

The separation of crude oil into fractions

Hydrocarbon fraction

A group of hydrocarbons with similar boiling points and numbers of carbon atoms

Fuel

A material that releases energy when it burns

Common hydrocarbon fractions

Petrol, diesel oil, kerosene, fuel oil, LPG

Petrol

A liquid fuel used in cars

Diesel

A liquid fuel used in large cars and trucks

Kerosene

A liquid fuel used in jet engines (planes)

Fuel oil

A liquid fuel for ships and power stations

LPG

a gas fuel used in cooking

Products made from crude oil

solvents, lubricants, polymers, detergents

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Evaporation

The change of state from a liquid to a gas

Condensation

The change of state from a gas to a liquid

1st step of fractional distillation in crude oil

Crude oil is heated and vapourised

Fractionating column

The vertical column, used in fractional distillation which is hottest at the bottom and cools towards the top

Hydrocarbon chain length

Number of carbon atoms in a hydrocarbon molecule

Shortest chains in fractional distillation

Are found at the top of the fractionating column

Longest chains in fractional distillation

Are found at the bottom of the fractionating column

Carboxylic acid

organic compounds that are weak acids

Functional group of carboxylic acids

-COOH

suffix of carboxylic acid

-anoic acid

Methanoic acid

CHOOH

Ethanoic acid

CH3COOH

Propanoic acid

CH3CH2COOH

Butanoic acid (display)

CH3CH2CH2COOH

Ethanoic acid + sodium carbonate -->

Sodium ethanoate + water + carbon dioxide

Solubility of carboxylic acids

soluble in water

pH of carboxylic acids

Less than 7

Observations of reactions

Same as those for strong acids, but with slower reactions

Carboxylic acid + alcohol -->

Ester + water

Esters

Fragrant organic compounds with -COOC- groups

Functional group of esters

-COOC-

ethyl ethanoate

CH3COOC2H5

Uses of esters

Solvents, perfumes and flavourings

Alcohols

Organic compounds containing OH group

Functional group alcohol

-OH

Suffix for alcohol

-anol

Methanol

CH3OH

Ethanol

C2H5OH

Propanol

C3H7OH

Butanol

C4H9OH

Combustion of alcohols

Burn completely in oxygen to form carbon dioxide and water

Alcohol + Sodium -->

Sodium alkoxide + hydrogen

Sodium + ethanol -->

Sodium ethoxide + hydrogen

Alcohols in water

Short chain alcohols dissolve easily in water

Oxidation of alcohols

Forms a carboxylic acid

Oxidising agents for alcohols

Potassium dichromate, bacterial enzymes

2 ways to produce ethanol

fermentation, hydration of ethene

Conditions of fermentation of glucose

yeast, glucose, warm temperature

Advantages of producing ethanol by fermentation

Uses renewable resources

Disadvantages of producing ethanol by fermentation

Labour intensive batch process

Advantages of hydration of ethene

Continuous process, 100% atom economy

Disadvantages of hydration of ethene

Uses finite resources

Uses of alchols

Solvents, fuels, drinks

Plastics

Synthetic polymers that can be molded or shaped

Polymers

Long molecules made by joining lots of monomers

Monomers

A small molecule that can join together with other small molecules to form polymers

Addition polymers

Alkenes (monomers) join up and the double bond is removed

Naming polymers

Poly(monomer)

Polymer made from ethene

Poly(ethene)

Condensation polymers

Polymers containing different functional groups form a long chain and a small molecule (usually water)

Polyester

A synthetic polymer linked by ester groups

Monomers for polyester

Diol, dicarboxylic acid