Chemistry - 9 Crude Oil and Fuels

Crude oil

Crude oil

petroleum that has not been processed

What is crude oil a mixture of?

different length hydrocarbons

Hydrocarbon

a compound containing only hydrogen and carbon

Fraction

a group of hydrocarbons with similar boiling points

Distillation

a process that separates the substances in a solution based on their boiling points

Alkane

a hydrocarbon containing only single covalent bonds

Alkanes are called ... hydrocarbons

saturated

What does it mean if a hydrocarbon is saturated?

it contains as many hydrogen molecules as possible

Meth-

1 carbon

Eth-

2 carbons

Prop-

3 carbons

But-

4 carbons

Methane

CH₄

Ethane

C₂H₆

Propane

C₃H₈

Butane

C₄H₁₀

Alkane general formula

CₙH₂ₙ₊₂

What kind of hydrocarbon is most useful?

short-chain hydrocarbons

Volatility

a measure of how readily a substance vaporizes

Short-chain hydrocarbon boiling points

lower boiling points

Short-chain hydrocarbon volatility

higher volatility

Short-chain hydrocarbon viscosity

lower viscosity

Short-chain hydrocarbon flammability

higher flammability

Fractional distillation

refining petroleum by separating compounds according to their boiling points

Fractionating column

a column used to separate fractions based upon their boiling points.

Residue

thick, sticky long-chain hydrocarbons

Residue use:

bitumen for roads and roofs

What happens to crude oil before it goes into a fractionating column?

it is vaporised

Complete combustion

a combustion reaction in which the only products are carbon dioxide and water

Oxidised

a substance that has had oxygen added to it

Blue cobalt chloride and water

goes from blue to pink

Anhydrous copper sulfate

goes from white to blue

Incomplete combustion

combustion where not enough oxygen is supplied

Products of incomplete combustion

carbon dioxide, carbon monoxide and water

What is cracking?

splitting up long chain hydrocarbons

Cracking process [2]:

- vaporise hydrocarbon
- pass over catalyst

What reaction is cracking an example of?

thermal decomposition

Cracker

a steel vessel in which cracking takes place

Alkene

an unsaturated hydrocarbon

Functional group

a characteristic that unites a homologous series

Homologous series

a series of organic compounds with the same functional group

Functional group of alkenes

C=C double bond

Test for unsaturated hydrocarbon

orange bromine water becomes colourless

Are alkanes or alkenes more reactive?

alkenes