ORGANIC-ALKENES

Question 1

What are alkenes

Answer 1

Unsaturated hydrocarbons with the general formula of CnH2n

Question 2

Features of C=C bond

Answer 2

Consist of one pi bond and one sigma bond
The pi bond has high electron density and so it id vulnerable to attack from electrophiles

Question 3

What causes am electrophillic addition

Answer 3

Double bonds have high electron density which attract electrophiles and results in alkenes undergoing addition reactions

Question 4

Br2 electrophillic addition

Answer 4

Forms 1-2 dibromoethane
The pi bond e- repel the electron pair in the br-br inducing a dipole making the br2 molecule polar and an electrophile

Question 5

HBr electrophillic addition

Answer 5

Forms 1-bromoethane

Question 6

H2SO4 electrophillic addition

Answer 6

2 stages - 2nd stage is hydrolysis which is the addition of water to breakdown a molecule
H2SO4 acts as a catalyst as its regenerated

Question 7

Major and minor products

Answer 7

Major product is when it’s attached to more hydrogen whereas minor product is less hydrogens
- whether the product produced is a major or minor products depends on which carbon molecule has the positive charge in the carbocation intermediate

Question 8

Stability of carbocation

Answer 8

Depends on how many alkyl groups are bonded to the carbon atom with the positive charge
tertiary - secondary - primary

Question 9

Markovinkoffs ruke

Question 10

What is pvc

Answer 10

Poly(chloroethene) it is a polymer that is waterproof and an electrical insulator but doesn’t react with acids

Question 11

Pure form of pvc

Answer 11

Rigid plastic due to strong intermolecular forces between polymer chains making them hard to move over each other

Question 12

Plasticiser

Answer 12

Weakens the intermolecular forces between the polymer chains making them easier to move and this form of pvc is used as an insulator on electrical wires