e. topic 5 - introduction to organic chemistry

molecular formular for methane

CH4

molecular formular for ethane

C2H6

molecular formular for propane

C3H8

molecular formular for butane

C4H10

what are the homologous series

a group of molecules with similar properties which therefore react in a similar way

what is the general formula for the homologous series alkanes

CnHn+2

what process of separation is used for crude oil

fractional distillation

what hydrocarbons are the most flammable (Best fuel)

the shortest

what is the texture of long hydrocarbons

thick and viscous

What is a hydrocarbon

A compound contain hydrogen and carbon atoms only

Crude oil is n__ - r____________

Non-renewable

Order hydrocarbons from the lowest boiling point to the highest boiling point

Refinery gases, gasoline, kerosene, diesel, fuel oil, bitumen

The _____ gets ______ down the list of crude oil hydrocarbons

Colour, darker

Why do hydrocarbons have a higher boiling point?

Because they are longer chains of hydrocarbons

In complete combustion there is _______ oxygen

Excess

In incomplete combustion there is _______ oxygen

Limited

What is cracking needed

Breaking long chains of hydrocarbons into shorter hydrocarbons

Cracking is described as _________ ___________

Thermal decomposition

Why is cracking needed?

To satisfy the need for short chain fuels

There are too many long chain hydrocarbons

Explain the 3 steps of catalytic cracking

1. Vapourise the hydrocarbon

2. Put it in contact with the catalyst (aluminium oxide)

3. Chains split into smaller chain hydrocarbons

Explain the 4 steps of steam cracking

1. Vapourise the hydrocarbon

2. Put it in contact with steam

3. Heat it to 600-700 degrees

4. Chains split into smaller chain hydrocarbons

What is the use of refinery gases

Heating and cooking

What is the use of gasoline

Car fuel

What is the function of kerosene

Jet fuel

What is the use of diesel

Bus and lorry fuel

What is the function of fuel oil

Industrial heating

What is the use of bitumen

Road surfacing and roofing

V______ increases going _______ the list

Viscosity, down