Fractional Distillation Flashcards
What is fractional distillation used for?
To separate different sized hydrocarbons
How is crude oil formed?
Heat, pressure, plants and animals, mainly plankton + lots of time
What are the non renewable fuels?
Coal, oil and gas
What does non renewable mean?
Once they’re gone they’re gone
What are the 4 steps in fractional distillation
- Oil is heated and it’s turned into a gas
- The temperature gradient in the column means that the gas condenses at different levels
- Longer hydrocarbons drain out at the bottom and smaller ones at the top
- End product is the crude oil mixture separated out into different fractions
Which hydrocarbons, long or short, have the higher boiling points?
Longer
What are some uses of crude oil in modern life?
- oil provides fuel for transport
2. Petrochemical industry uses crude oil as feedstock to make new compounds
What is cracking?
Splitting long chain hydrocarbons
What are the two methods used to crack a long hydrocarbon?
- Heating to vaporise and then pass the gas over a hot powdered aluminium oxide catalyst
- Heat to vaporise and mix with steam
What is the main difference between and alkane and alkene
The presence of a double bond
What makes an alkene more reactive than an alkane
The double bond
Why is an alkene known as being unsaturated?
The double bond can open out and bond to something else leaving a structure with only single bonds (saturated)
What is the general formula of an alkene?
CnH2n
Which form of combustion do alkenes undergo?
Incomplete combustion
What is the formula for incomplete combustion?
Alkene + oxygen -> Carbon dioxide + carbon monoxide + carbon + water
What colour is the smoke produced in incomplete combustion?
Smoky yellow
