Alkenes and Ethanol Flashcards
What are alkenes?
They are hydrocarbons which have a double bond between the two of the carbon atoms in their chain.
Why are alkenes known as unsaturated?
Because they can make more bonds.
The double bond can open up allowing two carbon atoms to bond with other atoms.
What are the first 2 alkenes?
Ethene - 2 carbon atoms.
Propene - 3 carbon atoms.
Carbon atoms always make what?
4 bonds.
Hydrogen atoms only make 1.
How can you test for an alkene?
By adding the substance to bromine water.
When an alkene comes in contact with bromine water what happens?
The alkene will decolourise the bromine water.
Turning it from orange to colourless.
Because the double bond has opened up and formed bond with the bromine.
Ethene can be hydrated with steam to produce what?
With the presence of a catalyst to make ethanol.
Pro about ethene?
Its a cheap process not much wasted.
Con about ethene?
Its produced from crude oil which is non renewal that could start running out fairly soon.
It will become expensive.
How can ethene also be produced from?
Renewable resources.
The alcohol in wine and beer etc is made from what?
Fermentation.
What is the raw material for fermentation?
Sugar.
What happens to the sugar in fermentation?
Its converted into ethanol using yeast.
What is the word equation for fermentation?
Sugar —-> carbon dioxide + ethanol.
The process fermentation needs what?
Lower temperatures and simpler equipment compared to using ethene.
