Organic 2 Flashcards
How is cracking carried out?
Hydrocarbons are vaporised then passed over a catalyst (silica/alumina) at a high temperature (600C- 700C)
Compared to alkanes, alkenes:
- boiling point
- saturated/unsaturated
- flammability
- viscosity
- bromine water test
- volatility
Have lower boiling points Are unsaturated Are more flammable Are less viscous Will turn from orange-> colourless in bromine water Are more volatile
Paraffin oil represents
Alkanes
The product represents
Alkenes
Definition of a monomer
A molecule that can join with many others to make a polymer
Problems with disposal of addition polymers
Plastics are inert and non biodegradable (cannot be broken down by living organisms).
One way to get rid of plastic waste is by burning it, however this can release toxic gases.
What makes alkenes unsaturated?
They do not only have single bonds and contain a carbon (C=C) double bond.
Bromine test for alkenes
result + explanation
Orange -> colourless
Dibromoalkenes are produced because the C=C bond breaks
Alkane test for bromine water result + explanation
No colour change because alkanes are highly unreactive.
Why is cracking necessary?
It helps to match the supply of fractions with the demand for them. Shorter chained hydrocarbons have a higher demand in the industry than longer chained hydrocarbons.
Definition of biodegradable
Can be broken down by living organisms
Alkenes functional group
> C=C
What conditions are needed for the reaction of steam with alkenes?
- 300 C
- 60-70 atm pressure
- catalyst of phosphoric acid
What kind of reaction do alkanes undergo and what conditions are needed for this to happen?
Substitution reactions - UV light is needed
What kind of reactions do alkenes undergo?
Addition reactions
