Chemistry: Crude Oil, Fractionating column, Alkanes

What is crude oil a mixture of?

hydrocarbons

What is fuel?

A Fuel is a substance which when burnt (combusted) releases heat energy

What is complete combustion and it’s product?

Fires with enough oxygen, Product is Carbon Dioxide (CO2) + Water

What is incomplete combustion and it’s product?

Fires without enough oxygen, Product is Carbon Monoxide (CO) + Water

What does refinery do to compound in oil?

separates them into simpler groups called fractions.

What are fractions?

mix of compound with similar number of carbon atoms.

What do refineries do to crude oils?

Monetize crude oil by transforming it into finished products

What are the fractions that crude oil are transformed into?

LPG, petenem feeds, gasoline, kerosene, jet fuel, diesel fuel, heating oil, asphalt, pet coke.

What does carsenogenic mean?

cancer-causing

Describe the process of a fractionating column

1. Oil is heated to about 370 degrees celcius and pumped into bottom of tall tower, where it vapourises.

2. As vaporised oil rises, it cools and condenses.

3. Heavy factions (contains large molecules), have high boiling pts and condenses near bottom of column. More bonds to break.

4. Lighter fractions (contains small molecules) have lower boiling pts and condenses further up. Less bonds to break.

Where is it hottest in the fractionating column?

Bottom, cooler at top. 

List the order of the crude oils from the bottom to the top in fractionating column.

Bitumen, fuel oil, diesel oil, kerosene, gasoline, refinery gases

Which crude oils are most likely to use as fuel?

Lower carbon atoms fractions as little heat is needed. 

What are the properties of the fractions at the top?

High flammability

Low viscosity

Low boiling points

Light colour

What are the properties of the fractions at the bottom?

Low flammability

High viscosity

High boiling points

Dark colour

What is viscosity?

how thick and runny a substance is

What is volatility?

How easily a substance changes from liquid or solid to a gas

What is energy content?

amount of heat energy released by fuel.

What are alkanes?

Saturated hydrocarbons

What does saturated mean in this context?

they only have single carbon-carbon bonds and are single covalent bonds.

Why can’t alkanes undergo additional reactions?

Since all bonds are taken, cannot add any more atoms to them and have no single bonds to react.

What alkanes examples of?

homologous series, which are group of organic compounds with the same functional group or chemical properties. 

What is the molecular and structural formula of methane?

Molecular formula: CH4

Structural formula: CH4

What is the molecular and structural formula of ethane?

Molecular formula: C2H6

Structural formula: CH3 CH3

What is the molecular and structural formula of propane?

Molecular formula: C3H8

Structural formula: CH3 CH2 CH3

What is the molecular and structural formula of butane?

Molecular formula: C4H10

Structural formula: CH3 CH2 CH2 CH3

What is the general formula for alkanes?

The general formula of the alkanes is C_nH_2n+2

Which two reactions can alkanes only undergo?

Combustion and substitution with halogens

Wa is the formula for combustion in alkanes?

Alkane + oxygen → carbon + water 

What is substitution?

When one atom (or group of atoms) is replaced by another atom (or group of atoms)

How can substitution only happen?

One at a time and only one hydrogen gets replaced at a time.

What is the prefix in substitution reactions of alkanes?

Added to the name of the alkane depending on what halogen are attached.

Name the prefix of all the halogens

Florine: Fluoro

Chlorine: Chloro

Bromine: Bromo

Iodine: Iodo

Name the prefixes by numbers

2 = di

3 = tri

4 = tetra

5 = penta