Cracking and alkenes Flashcards
Why do hydrocarbons need to be cracked to produce shorter chain hydrocarbons
Long-chain hydrocarbons have very low flammability, this makes them useless.
Cracking them to produce shorter chain hydrocarbons makes them more useful for fuels
Name the two different methods of cracking
Catalytic cracking
Steam cracking
What conditions are necessary for the catalytic cracking of hydrocarbons?
High temperature
Catalyst
What conditions are necessary for steam cracking?
High temperature
Steam
What are the products of cracking long-chain alkane hydrocarbons?
A shorter chain alkane hydrocarbon + alkene
Are alkenes more or less reactive than alkanes?
More reactive
Are alkanes more or less reactive than alkenes?
Less reactive
Describe the test to test for alkenes
Pour an bromine water into a test tube. Bromine water is orange.
Add a few drops of an alkene. The alakene will cause the bromine water to change colour from orange to colourless
There is a _ _ _ _ demand for fuels with small molecules
fill in the blank
There is a high demand for fuels with small molecules
What are the products of cracking useful for?
Fuels
When balancing an equation which shows the cracking of a long-chain alkane hydrocarbon, what must you make sure there is
An equal number or carbon and hydrogen molecules on either side once i have ** finished balancing**
What are short-chain alkene hydrocarbons useful for
Polymers
What is the general formula for alkenes?
CnH2n
simples 😋
In cracking, name a different product that can be produced instead of a shorter-chain alkane
Alkene
Why do alkenes decolourise bromine water but alkanes do not?
Alkenes are more reactive and so they react with and decolourise bromine water but alkanes do not
