please explain geometrical isomerisam in in alkenes with diagram for easily understandig

3 years ago


Answers : (1)


Dear student,

Geometrical isomerism is a kind of stereoisomerism. The isomerism due to the difference in spatial arrangements of groups about the doubly bonded carbon atoms is known as Geometrical Isomerism.

For e.g., consider the structure of 2-butene.

Space Models

Space Models of 2-Butenes


fig.12.1 - Space Models of 2-Butenes

Note that the atoms are arranged in two different ways in I and II. The two CH3 groups lie on the same side in I and on the opposite sides in II. When two similar atoms or groups lie on the same side, the isomerism is called cis isomerism and the isomers are called cis isomers (cis means "on same side" in Latin). When two similar atoms or groups lie on opposite sides, the isomerism is called trans isomerism and the isomers are called trans isomers (trans means "across" in Latin). Geometrical isomerism is also called Cis-trans isomerism.

The carbon-carbon double bond in 2-butene consists of one sigma bond and one pie bond. The pie bond is formed by the lateral overlapping of p orbitals that lie above and below the sigma orbital plane. To pass from the cis form to the trans form, the molecule must be twisted so that the p orbitals don't overlap any more and the pie bond is broken. To break this pie bond, around 167.2KJ of energy is required. Therefore the conversion from one geometric isomer to another is very rare in 2-butene.


Hindered rotation about the carbon carbon double bond


fig.12.2 - Hindered rotation about the carbon carbon double bond

Similarly, maleic and fumaric acids exhibit geometric isomerism or they are geometric isomers.

maleic acid and fumaric acid are geometric isomers
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 Acetaldehyde is more soluble than Formaldehyde in water !
There is no H-bonding in both Acetaldehyde and Formaldehyde. So solubility depends on the vanderwaals forces of attractions which are proportional to molecular weight of compounds. Since MW...
Ramreddy 2 months ago
@ramreddy sir , but then why Propanal is less soluble than Ethanal ? Also, in most of the texts we found that solublitity is inversely prop. to Hydrophobic(Alkyl) Part Conc. …
Navdeep Kumar 2 months ago
what should i refer ,o p tandon or ranjeet shahi ?,if i need theory as well as ques at the same time
If you need theory then follow o.p.tandon or if you want to questions then follow ranjeet shahi. But it is better to follow o p tandon for both theory as well as questions....
Ramreddy 2 months ago
thank you sir
sunath khadikar 2 months ago
Explain the formation of alcohols From Grignard reagents?
All the three types of monohydric alcohols (primary, secondary and tertiary alcohols) are obtained by the use of Grignard reagents and carbonyl compounds. The addition of RMgX on carbonyl...
Pankaj 4 months ago
how to caluculate screenig constant
Dear student, We know that in quite a few atoms, each of the constituent electron is said to experience less than the actual nuclear charge because of shielding or screening by the other...
Sumit Majumdar 4 months ago
8 g sample of KMnO4 is reacted in acidic medium with 100 ml of 10 volume H2O2.The % purity of KMnO4 sample is.?
KMnO4....+H2O2.....................>O2..+H 2 O......+Mn2+..............(i)..(Unbalenced form) 10 volume H2O2means that If 1 litre of H2O2 solution is taken tgen it will liberate 10 litre...
Naveen Kumar 25 days ago
Dear Student, this method seems to be lengthy but it was for your understanding the basic concepts, not simply for the solving question; as your question require all the given in formation...
Naveen Kumar 19 days ago
sir,is there any other method as well.?
Shriya Mehrotra 25 days ago
Can you please suggest a good book for physical chemistry level of iit jee ?
yes my dear friend very simple and you can have excellent command over physical chemistry step (1)read ncert ( 2)read optandon simultaneously with ncert chapter (3)solve problem from...
Sunil Kumar FP 4 months ago
what you say about ananya ganguly?
harit 3 months ago
View all Questions »