Topic 7 - Organic Chemistry Flashcards
What is Crude Oil?
Crude Oil is a mixture of Hydrocarbons.
What is a Hydrocarbon?
A Hydrocarbon is any amount of ONLY Hydrogen and Carbon bonded together in a molecule.
What is an Alkane?
compounds that consist entirely of single covalently bonded carbon and hydrogen atoms
What are Saturated Hydrocarbons?
Alkanes are saturated Hydrocarbons, this means that all the Carbon atoms are connected to eachother with a single covalent bond.
What is the formula of Alkanes?
C(n)H(2n+2)
How is Crude Oil separated?
Crude Oil is separated by Fractional Distillation, this separates crude oil into different fractions.
What are the fractions of Crude Oil made up of?
The fractions are made up of molecules of simlar Carbon chain length.
Explain the process used to separate Crude Oil.
Potential 4-6 marker..
1.Crude Oil is heated up before entering a fractioning column, to vapourise it into a gas.
2.These gas molecules rise up the column.
3.The column is hotter at the bottom than the top.
4.As the column cools, each fraction condenses at its boiling temperature.
5.This separates the Fractions.
What do we do with the fractions?
We often use the fractions as Fuels and Feedstocks.
Which fractions are used as fuels?
We use the smaller fractions as fuels - releasing their energy through combustion.
What fractions are used as feedstocks.
We use many of the larger chain molecules as feedstocks for other producs, these usually undergo further reactions.
What are feedstocks?
Feedstocks are materials that are used to produce something in an industrial process
What does volatility mean?
How easy something evaporates
What does viscosity mean?
How runny a substance is
What energy is stored in fuels, and how is it released?
Chemical store, and it is released by combustion
What is the rule for how the length of the carbon chain effects the substances: flammability, viscosity, boiling point and volatility
With a longer carbon chain, the:
1.Flammability decreases
2.volatility decreases
3.boiling point increases
4.viscosity increases
What is the general word equation for the combustion of hydrocarbons?
Hydrocarbon+oxygen –> Carbon dioxide + Water
What are Alkenes?
Alkenes are unsaturated hydrocarbons
Why are Alkenes unsaturated?
They are unsaturated because they have a double bond between 2 carbon atoms.
How many double bonds are there in each Alkene molecule?
ONE
What are the 4 Alkanes you need to remember?
1.Methane
2.Ethane
3.Propane
4.Butane
What are the 3 Alkenes you need to remember?
- Ethene
- Propene
- Butene
What is the general formula for Alkenes?
CnH(2n)
What is an Homologous series?
A group of chemicals that behave in a similar way that have the same functional group and general formula.
What is the test for Alkenes?
Bromine water goes from orange to colourless when alkene added.
Where do alkenes come from?
- Longer hydrocarbons have less demand but high supply
- Shorter hydrocarbons have high demand but low supply
- Longer hydrocarbons are broken using CRACKING.
- This produces 2 Hydrocarbons (1Alkene) (1Alkane)