1. Alkenes and electrophiles

2. Alkene reactions
When alkenes react they gain new atoms, what do you think we call this type of reaction?
Addition reactions

3. The Double bond The double bond is made of a sigma bond and a pi bond
What is a sigma bond?

4. Sigma bond When two s-orbitals overlap
This gives high electron density
It is like the single bond

5. Pi Bond When two p orbitals overlap What shape would this be…?
The bond will have two parts one above and one below the “molecular axis”

6. The Double bond
The sigma bond is wedged in between the two parts of the pi bond,
Because the double bond has a high electron density it allows reactions to happen
It is the pi bond that will be involved in the reaction

7. Electrophiles They love electrons (they are electron pair acceptors
They really want to gain electrons
For example positively charged ions
Or delta + parts of polar molecules
The reaction we are looking at is called electrophilic addition

8. Nucleophiles
The are willing to give up electrons pairs (to an electrophile)
For example the C-C double bond

9. Reactions
What reactions can you remember from gcse?

10. Hydrogenation
Conditions 150 degrees Celsius and a nickel catalyst

11. With bromine water
Both unsymmetrical alkenes like propene and symmetrical alkenes like but-2-ene

12. With Bromine

13. With Steam Conditions 300 degrees Celcius 60 to 70 atm pressure
Solid Phosphoric acid catalyst (H3PO4)
Reversible reaction