how to determine the stability of carbocation and what is the concept of bridge carbon

4 years ago


Answers : (1)


Dear student,

We know that methyl group is electron releasing i.e. has +I inductive effect. The alkyl group attached to positively charged carbon atom tends to release electrons towards carbon. This decreases the positive charge on the carbon atom but the carbon itself is somewhat positive. As a result, the positive charge on the carbon atom gets dispersed, giving it stability. Therefore, more the number of alkyl groups, the greater will be the dispersal of charge and therefore, more stable will be the carbocation.

Thus, tertiary carbocation in which there are three alkyl groups attached to positive carbon is more stable than a secondary carbocation with two alkyl groups. Similarly, a secondary carbocation is more stable than a primary carbocation, which in turn is more stable than methyl carbocation:

stability of carbocations

Thus, the order of stability is: CH3+ < 1o < 2o < 3o

Other carbocations are benzyl carbocation, which is primary in nature but is highly stable because of resonance stabilization.


resonance stabilization of carbocations

Triphenyl carbocation, Ph3C+ is the most stable because of resonance stabilization among three phenyl groups.

Please feel free to ask your queries here. We are all IITians and here to help you in your IIT JEE preparation.

All the best.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..


Askiitians Expert

Sagar Singh

B.Tech, IIT Delhi

3 years ago

Post Your Answer

More Questions On Organic Chemistry

Ask Experts

Have any Question? Ask Experts
Post Question
Answer ‘n’ Earn
Attractive Gift
To Win!!!
Click Here for details
why alcoholic.KOH gives elimination reaction but aqueous.KOH gives substitution reaction?
Aqueous KOH is alkaline in nature i.e. It gives OH - . These hydroxyde ions ions which act as strong nucleophile and replace halogen atom from alkyl halide. RCl + KOH (aq.) → ROH. This...
sumit kumar one month ago
what is heat of hydrogenation
Heat of hydrogenation is the energy released when a pi bond is converted to a sigma bond by the addition of hydrogen. The greater the heat of hydrogenation, the greater the potential energy...
Ashwin 14 days ago
Describe the basic of organic chemistry. what is the scope of organic chemistry in our society?
Organic Chemistry is the branch of chemistry which involves the study of organic compounds.Organic compounds are the compounds obtained from living organisms like plants and animals.All such...
Aarti Gupta 29 days ago
If avogadro’s no. is taken as any no. other than 6.023×10 23 , will there be any change in the molecular mass of any molecule (for instance O 2 ) ??
Molecular mass of an substance (element or compound) is the average relative mass of a molecule of the substance as compared with mass of an atom of carbon(C-12) taken as 12u.It tell us the...
Aarti Gupta yesterday
If a peice of iron gains 10% of its weight due to partial rusting into Fe2O3 the percentage of total iron that has rusted is 23 13 23.3 25.67
4Fe + 3O2----2Fe2O3 let the weight of fe conveerted to fe2o3 be x gm initian total weight be 100gm now weight gain=110gm mole of fe conveerted to fe2o3=4x/56 mole of fe2o3=x/56*2 weight of...
Sunil Kumar FP one month ago
What are its effects on temperature, effect on inert gases, effect on pressure ,etc?
inert gas are basically having fully filled they are highly unreactive and there is small effect. i thinh you are asking equilibrium question. lee chatlers principle effect of...
Sunil Kumar FP 14 days ago
View all Questions »