Organic chemistry Flashcards
What’s a hydrocarbon?
Molecules made up of hydrogen and carbon atoms only
What’s an Alkane?
A hydrocarbon, a line of carbon atoms surrounded by Hydrogen atoms
Formula for Methane?
CH4
Formula for Ethane?
C2H6
Formula for Propane?
C3H8
Formula for Butane?
C4H10
Formula for pentane?
C5H12
What’s the general formula for an Alkane?
Cn H2n+2
What’s the alkane when no more atoms can join on to the carbon atoms?
Saturated
What’s complete combustion?
When an Alkanes burn with a lot of oxygen available, Alkane + Oxygen = Carbon dioxide + water
How do you there’s been complete combustion?
Blue flame
What’s incomplete combustion?
When an alkane burns without enough oxygen, producing carbon and the poisonous carbon monoxide. So Alkane + oxygen = carbon + Carbon monoxide + Carbon Dioxide + water
What happens when a Halogen reacts with an Alkane?
Produces Haloalkanes (in the presence of UV light)
What is a Haloalkane
When the Halogen replaces one of the Hydrogens in the Alkane producing eg. a Bromomethane
What’s an Alkene?
Hydrocarbons with a carbon double bond
Unsaturated as they can make more bonds
General formula for an Alkene?
Cn H2n
Formula for Ethene?
C2H4
Formula for Propene?
C3H6
Formula for Butene?
C4H8
What’s it called when 2 molecules have identical molecular formulas, but different structures?
Isomers
What happens when a halogen reacts with an alkene?
They form a Haloalkanes
What’s a Haloalkene?
When a halogen splits the carbon double bond, and 2 halogen bond to the available carbons (an addition reaction)
How do you test for carbon double bonds?
If you shake orange bromine water with the solution and it becomes colourless then the halogens have reacted with the carbon double bonds
How do you make Ethanol?
With Ethene and steam
What temperature is required to make Ethanol?
300C
What pressure is required to make Ethanol?
60-70 atmospheres
What’s the catalyst used in the making of Ethanol?
Phosphoric acid
Why will making Ethanol become expensive?
Crude oil is a non renewable resource
What other way can Ethanol be produced?
Fermentation
What’s fermentation?
When sugar is made into ethanol using yeast
Advantage of Fermentation?
Sugar and yeast are renewable
Cheap equipment
Disadvantage of fermentation?
Isn’t very concentrated, so it needs to be distilled and purified
Slow reaction
Expensive labour
What temperature is Fermentation done at?
30C
Advantages of Ethene + steam?
Ethene’s cheap
Little is wasted
Cheap labour
Pure product
Disadvantages of Ethene + steam?
Non renewable resource of Crude oil
Expensive equipment
How can you turn Ethanol back into Ethene?
Dehydration reaction
How is the dehydration reaction done?
Ethanol vapour passed over a hot catalyst of aluminium Oxide
