Alkenes ( addition reactions of alkenes) Flashcards
Define hydrolysis
A reaction where the molecule is split by the addition of water
What do you use to test for unsaturation?
Bromine.
Name three conditions for the production of ethanol from ethene:
- Temperature between 300oC and 600oC.
- 60atm of pressure.
- Phosphoric catalyst.
Define electrophile
An electron pair acceptor
What is the mechanism for changing an alkene to a dihaloalkane?
Electrophilic addition
What are the conditions for electrophilic addition of alkenes?
Room temperature
What is a carbocation?
An intermediate formed which has a positive charge on the carbon atom
What are the three reagents that alkenes react with in electrophilic addition?
Bromine, HCl/HBr and concentrated Sulphuric acid
How many products are formed when the alkene is unsymmetrical?
Two
Why is HBr/HCl a polar molecule?
Br/Cl are more electronegative than H
Why is the carbocation more stable if it is tertiary rather than primary?
The methyl group on either side of the positive carbon are electron releasing and so reduce the charge on the ion which stabilises it
What is Markownikoff’s rule?
The hydrogen goes to the carbon with the most hydrogen atoms attached to it
What is the order of stability in carbocations?
Tertiary > secondary > primary
How are alcohols produced from alkenes in industry?
Hydration
What is the catalyst used, and at what temperature, in hydrogenation of alkenes?
Nickel catalyst at 140 degrees
