All alkanes are ______________
Hydrocarbons
What are hydrocarbons
Molecules that are made up of hydrogen and carbon atoms only
Alkanes are chains of ___________ atoms surrounded by ______________ atoms
Carbon
Hydrogen
Different alkanes have chains of different __________
Lengths
What are the first 5 alkanes
Must Every Prefect be Perfect
Methane Ethane Propane Butane Pentane
What is the formula of an alkane
Cn H2n+2
What is a homologous series
A group of compounds that can all be represented by the same general formula
What does biodegradable mean
Capable of being decomposed by bacteria or other living organisms and thereby avoiding pollution.
Most polymers, including poly(ethene) and poly(propene), are not ________________
Biodegradable
What does saturated mean
Containing the greatest possible number of hydrogen atoms, without carbon–carbon double or triple bonds.
When there is lots of oxygen, ____________ combustion occurs
Complete
Complete combustion: Alkane + oxygen → _________ __________ + ___________
Carbon dioxide + water
What is produced when an alkane is burnt
Carbon dioxide and water
Incomplete combustion: Alkane + oxygen → …
Alkane + oxygen → carbon + carbon monoxide + carbon dioxide + water
Incomplete combustion means a _________ ___________ flame, and ________ energy than complete combustion
Smoky yellow flame
Less
Halogens react with alkanes to make _____________
Haloalkanes
_____________ and bromine react with alkenes in the presence of ____ light
Chlorine
UV (Ultraviolet)
In haloalkane reactions, a hydrogen atom from the alkane is substituted (replaced) by _____________ or ___________ and there will also be an extra hydrogen ___________ or hydrogen ___________ molecule.
Chlorine or bromine
Alkenes are another type of _____________
Hydrocarbon
How are alkenes different to alkanes
Alkenes contain double bonds whereas alkanes don’t
____________ are unsaturated
Alkenes
What are the first three alkenes
Every Penguin Burps
Ethene
Propene
Butene
Why is methene not a thing
Because methane cannot have a double bond since there is only 1 carbon
Halogens can react with alkenes to make haloalkanes. Why is this called an addition reaction
HaloalkAnes
Because the double carbon bond is split and a halogen atom is added to each of the carbons
(A halogen atom is Bromine or Chlorine)
The reaction between bromine and alkenes is often used as a test for __________ bonds
Double bonds
When you shake an alkene with orange bromine water, the solution becomes ______________ - this is because the bromine molecules, which are orange, are reacting with the alkene to make a dibromoalkene, which is colourless
Colourless
Ethanol can be produced from ___________ and __________
Ethene and steam
Ethene is produced from __________ ______
Crude oil
Ethene will react with steam to make _____________
Ethanol
To make ethanol using ethene and steam you need a temperature of ______ and a pressure of ___-___ atmospheres
300°C
60-70
What is used as a catalyst in the reaction between ethene and steam
Phosphoric acid
What type of process is used to make ethanol using ethene + steam
Continuous
Which process of making ethanol has a quicker reaction speed
Ethene + steam is quicker
The ethanol made in ethene + steam is ______
Pure
The ethanol made in fermentation is _________
Impure
Which process used to make ethanol is renewable
Fermentation is renewable
Ethene + steam is non-renewable because it uses crude oil to get the ethene
What temperature is needed to create ethanol using fermentation
30°C
What pressure is needed to create ethanol using fermentation
1 atmosphere (normal pressure)
Which process used to make ethanol is cheaper
Fermentation is far cheaper
Ethene + steam is expensive to build and expensive to maintain
Which process is used to make ethanol release co2
Fermentation
What type of process is used to create ethanol using fermentation
Batch
Ethanol can be dehydrated to form ____________. This is done by removing ___________ from the ethanol in a dehydration reaction. Ethanol vapour is passed over a hot catalyst of ________________ oxide - the catalyst provides a huge surface area for the reaction
Ethene
Water
Aluminium
How to differentiate between alkanes and alkenes:
Add a few drops of bromine water:
Alkenes decolourise it
Alkanes don’t (remains orange)
Symbol equation for complete combustion of alkanes
CH4 + 2O2 –> CO2 + 2H2O
Fermentation of sugars equation
Sugar–> ethanol + carbon dioxide
Ethene + steam equation
Ethene + water (steam) –> Ethanol
How is ethanol dehydrated to make ethene
By passing ethanol vapour over a hot catalyst of aluminium oxide