Chemistry Chapter 8 | 2nd Year

 Chapter 8 Notes | Chemistry 2nd Year

“Aliphatic Hydrocarbons”

1. Hydrocarbons are made up of carbon and hydrogen only. Saturated hydrocarbons are called alkanes. They do not contain functional groups.
2. Alkanes react with halogen by a radical mechanism ti give haloalkanes mechanism consists of three steps, initiation, propagation and termination.
3. Alkenes are very reactive compounds. They undergo electroscopic reactions easily.
4. Addition of unsymmetrical reagent to an unsymmetrical alken takes place accordance with the Markownikov’s rule.
5. Hydrocarbons containing a triple bond are known as alkynes or acetylenes.
6. Alkynes underho addition reaction and two molecules of a reagent are added in it.
7. Etyne and other terminal alkynes contain a weakly acidic hydrogen and therreact with ammocial cupprous chloride and ammocial silver nitrate to give acetylide.
8. The decreasing reactivity order alkanes, alkenes and alkynes are as follows:
   Aklenes>Alkynes>Alkanes