3.4 Alkenes Flashcards
Use your understanding of the properties of PVC to explain whether you would expect to find a plasticiser in the PVC used to insulate electrical cables.
- it is present
* because PVC needs to be flexible / bendy( and plasticisers reduce brittleness)
Explain why the two products are formed in different amounts when electrophilic addition occurs.(2)
The major product is formed via a tertiary carbocation intermediate and the minor product is formed via a secondary carbocation intermediate
The tertiary carbocation is more stable than the secondary carbocation
How do you form a dihalogenoalkane from an alkene, what are the reagents and conditions?
Reagent: Bromine
Conditions: Room temperature (not in UV light) Mechanism: Electrophilic Addition
Type of reagent: Electrophile, Br2+
How do you form a halogenoalkane from an alkene, what are the reagents and conditions?
Reagent: HCl or HBr
Conditions: Room temperature
Mechanism: Electrophilic Addition
Type of reagent: Electrophile,
What is the most stable carbonation type?
Tertiary
What is the major product in electrophilic addition of alkene?
In electrophilic addition to alkenes, the major product is formed via the more stable carbocation intermediate.
How do you form an alkyl hydrogensulfate from an alkene, what are the reagents and conditions?
Reagents: concentrated H2SO4
Conditions: room temperature
Mechanism: Electrophilic Addition
Type of reagent: Electrophile, H2SO4
How do you form an alcohol from an alkyl hydrogensulfate, what are the reagents and conditions?
Reagents: water
Conditions: warm mixture
Type of reaction: hydrolysis
What are the conditions for the industrial hydration of alleges to form alcohol?
High temperature 300 to 600°C
High pressure 70 atm
Catalyst of concentrated H3PO4
How do you test for an alkene?
Bromine water will turn colourless if alkene is present.
