Alkenes - Conceptual Questions

1. What are alkenes?
2. Comment on the C=C bond length in ethane with respect to C-C bond length in ethane.
3. What is the IUPAC nomenclature systems for alkenes?
4. What is the IUPAC nomenclature with alkenes having two or more double bonds?
5. Discuss structural isomerism in alkenes.
6. Discuss geometrical isomerism in alkenes.
7. Geometrical isomers have different physical properties but simimar chemical properties. Write down how physical properties are different between cis and trans isomers of alkenes.
8. Explain E-Z system for geometrical isomers.
9. Comment on the stability of alkenes?
10. Explain the preparation of alkene for the following methods.

i. from alcohols.
ii. from alkyl halides
iii. from dihalogen derivatives
iv. from alkynes
v. by electrolysis of potassium salts of dicarboxylic acids (Kolbe reaction)

11. What are physical properties of alkenes?
a. Physical state and smell
b. melting points
c. Boiling points
d. Solubility in water
e. Dipole moments

12. Explain the following chemical properties of alkenes.

A. Addition reactions
a. Explain the reaction mechanism of electrophilic addition reactiosn of alkenes.

i. Addition of halogens
ii. Addition of of halogen acids
iii. Addition of water (hydration)
iv. Addition of hypohalous acid

B. Oxidation reactions
i. Combustion
ii. Hydroboration
iii. Oxidation of potassium permanganate
iv. Catalytic oxidation
v. Oxidation with ozone

C. Reduction

D. Polymerisation reactions
i. Polymerisation of ethane
ii. Polymerisation of vinyl chloride
iii. Polymerisation of styrene
iv. Polymerisation of tetrafluoroethylene

13. What are alkadienes? What is their relation to alkynes?
14. Explain the following terms:
a. conjugated dienes.
b. Isolated dienes
c. Cumulated diens or allenes.

15. Discuss stability of conjugated dienes.
16. Explain the concept of delocalisation of electrons in dienes.

17. Explain the following reactins of dienes
i. Electrophilic addition to conjugated dienes