Crude Oil

A Hydrocarbon is any compound that is formed from carbon and hydrogen atoms only.

Alkanes are the simplest type of hydrocarbon. Their simple formula is:

CnH2n+2

Short-chain hydrocarbons are flammable so make good fuels and are in high demmand.

You need to be able to balance chemical equations for cracking.

Crude oil is called a fossil fuel because?  it is formed from the remains of ancient sea creatures

What happens to a liquid during its separation from a mixture by distillation? Evaporating followed by condensing

The top of an oil fractionating column is?  Colder than the bottom of the column

Compared to large hydrocarbons, small hydrocarbons are? more volatile

Oil wells form when oil and gas are trapped by? impermeable rock

Which process allows large hydrocarbons to be broken down into smaller hydrocarbons?  cracking

The Alkanes are a Homologus series - group of organic compounds react similar way.

Saturated compounds - each carbon atom forms 4 single covalent bonds.

First 4 alkanes are: Methane, Ethane, Propane & Butane. (Mice Eat Peanut Butter)

Drawings showing all atoms and bonds in a molecule called a displayed formula.

Hydrocarbon properties change as the chain gets longer.

As the length of carbon chain changes, properties of the Hydrocarbon change.

1) Shorter the carbon chain,more runny the Hydrocarbon is - less gloopy. (Viscous)

2) Shorter the carbon chain, more Volatile the Hydrocarbon, meaning it turns into a gas at lower temp. Shorter carbon chain, lower the temp that the hydrocarbon vaporises or condenses and lower its boiling point.

3) Shorter - More Flammable the Hydrocarbon is.

Properties of Hydrocarbons affect how used for fuel.

Short chained lower boilng points used as bottle gases, stored under pressure as liquids in bottles.

Complete Combustion Occurs when plenty of Oxygen. CC of any Hydrocarbon in Oxygen releases lots of energy.

Only Waste products, Carbon Dioxide & Water Vapour.

Hydrocarbon + Oxygen -> Carbon Dioxide + Water + Energy

During Combustion, both Carbon and Hydrogen from the Hydrocarbon are Oxidised.

Hydrocarbons used as fuels due to amount of energy released when they combust completely.

Shorter Hydrocarbons are less viscous, more volatile and easier to ignite than longer hydrocarbons

Fossil fuels like coal, oil and gas are called non-renewable fuels.

Finite - Being used up faster than they can be produced.

Renewable - Being used up at the same rate they are being produced.

Crude Oil is a mixture of lots of different Hydrocarbons,most are alkanes.

The Different compounds in crude oil are seperated by fractional distillation.

Oil provides fuel for most modern transport, Diesel oil, Kerosene, heavy fuel oil and LPG all from Crude.

Petrochemical industry uses some of the Hydrocarbons from crude as feedstock to make new compounds.Used in polymers, solvents,lubricants & detergents.

All products from Crude Oil, examples of Organic Compounds. (compounds containing carbon atoms)

Carbon Atoms can bond together to form different groups, Homologous Series. they contain Similar compounds.

Cracking - splitting up long chain Hydrocarbons.

Short Chain Hydrocarbons, flammable so make good fuels, high demand.

Long chain Hydrocarbons form thick gloopy liquids like tar, which aren't that useful.

As a result, a lot of the longer alkane molecules produced from Fracking Distillation, turned into smaller, more useful ones, by cracking.

Cracking also produces another type of Hydrocarbon callled Alkenes, they are used as a starting material when making lots of compounds and can be used to make Polymers.

Bromine Water used to test for Alkelenes.

Orange Bromide water added to ALKANE, no reaction. Added to ALKENE, reaction occurs, ALKENES more reactive. - Colourless compound produced and Bromide water decolourised.

Different methods of Cracking.

Cracking is Thermal Decomposition reaction - breaking molecules down by heating.

1st step, heat long chain hydrocarbons to vaporise.

vapour passed over hot powdered aluminium oxide catalyst.

Long chain molecules split apart on surface of specks of catalyst - catalytic cracking.

crack Hydrocarbons if you vaporise them, mix with steam and heat to high temp, steam cracking.

Name the first four alkanes.  Methane, Ethane, Propane, Butane.  

Why are alkanes often used as fuels? When burnt they release energy

What is a hydrocarbon? A compound containing only carbon and hydrogen atoms.

What are the typical products of cracking? A short alkene and a short alkane.

What is the simple formula of an alkane?  CnH2n

Approximately how many carbon atoms might be linked together in a polymer molecule? Ten thousand

What name is given to the small molecules that can be joined together to form a polymer? Monomer

What feature of alkene molecules allows them to act as monomers? The double C=C bond

What monomer would be used to make the polymer poly(propene)? Propene

Name an alkane  Cyclohexane

When hydrocarbons like the alkanes burn in plenty of air, what type of reaction takes place? Conplete combustion

Name an alkene  Ethene

How do you test for an alkene? They turn Bromine water colourless