Alkenes

Question 1

why is there no rotation around the c=c bond

Answer 1

If rotated the pie bond formed by overlap of P orbitals would be lost and the bond will break

Question 2

Define electrophile

Answer 2

Accepts electron pairs

Question 3

Allene to a haloalkane

Answer 3

Reagent: HCL
electrophillic addition
CH2CH2 + HBr—> CH2BrCH3

Question 4

What is a positive inductive effect

Answer 4

Alkyl groups donate electron density through a covalent bond

Question 5

Why are tertiary carbons more stable

Answer 5

3 carbocation has more of a positive inductive effect because they are more alkyl groups bonded.

Question 6

Alkene To haloalkane with halogens

Answer 6

Reagent: Br2, I2, Cl2
Electrophillic addition
CH2CH2 + Br2–> CH2BrCH2Br

Question 7

Why does bromine react even though its a non-polar molecule

Answer 7

C=c is electron rich- induces a dipole across the Br2 molecule. The d+ Br accepts electron pair.

Question 8

Chemical test for alkanes

Answer 8

Bromine water- orange to colourless

Question 9

Alkene and H2SO4

Answer 9

Reagent: H2SO4
Produces Alkly hydrogen sulfate
Electrophillic addition
CH2CH2 + H2SO4 —> CH3CH2OSO3H

Question 10

Direct hydration

Answer 10

Reagent: H20
Condition: Conc H3PO4 Catalyst
Produces alcohol