Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

Chemistry Class 11

NEET : Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

The document Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev is a part of the NEET Course Chemistry Class 11.
All you need of NEET at this link: NEET

Hydrocarbons are the organic compounds containing carbon and hydrogen only, e.g., alkane, alkene and alkynes.

Classification of Hydrocarbons Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRevTypes of Hydrocarbons

Alkanes:

Alkanes are saturated, open chain hydrocarbons containing carbon-carbon single bonds. e.g., methane (CH4), ethane (C4H6) and propane (C3H8), etc.

These hydrocarbons are inert under normal conditions [i.e.,do not react with acids. bases and other reagents). Hence, they were earlier known as paraffins (Latin : parum-little; affins-affinity).

Alkanes exhibit chain isomerism, position isomerism and conformational isomerism.


Methods of Preparation of Alkanes:

i) From hydrogenation of alkenes and alkynes

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

Ease of hydrogenation depends on the steric crowding across the multiple bond. More is the steric crowding, the less is the reactivity towards hydrogenation.

(ii) By sodalime

Decarboxylation of sodium or potassium salts of fatty acids. [decarboxylation reaction]

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

This reaction is used for descending of series as the alkane obtained has one carbon less than the parent compound. CaO is more hygroscopic than NaOH and it keeps NaOH in dry state.—→

(iii) By Wurtz reaction

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

This reaction is used to increase the length of the carbon chain.

(iv) By reduction of alkyl halides

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

Reducing agents like Zn/HCl, HI/Red P, H2/Pd can also be used.

(v) By Kolbe’s electrolysis

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

Only alkanes with even number of carbon atoms can be formed.

Alkane and CO2 are liberated at anode while H2 is liberated at cathode.


(vi) Clemmensen’s reduction

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

(vii) From compounds containing oxygen

Alcohols, aldehydes, ketones, carboxylic acids and their derivatives give alkane when treated with hot conc HI and red P in a sealed tube.

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

(viii) Wolff-Kishner's reduction

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

(ix) From carbides

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

(x) Corey-Bouse synthesis

This method can be used to prepare alkanes having odd number of carbon atoms.

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Related Searches

Exam

,

Viva Questions

,

MCQs

,

Previous Year Questions with Solutions

,

Summary

,

Semester Notes

,

Extra Questions

,

mock tests for examination

,

past year papers

,

ppt

,

video lectures

,

Free

,

pdf

,

Objective type Questions

,

shortcuts and tricks

,

practice quizzes

,

Important questions

,

Sample Paper

,

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

,

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

,

Hydrocarbons and Methods of Preparation of Alkanes Class 11 Notes | EduRev

,

study material

;