PMDC Verified Question 2 of 83
Which type of isomerism is displayed by compounds having same structural formula but different position of atoms on both sides of carbon double bond?
A
Chain
B
Geometric
C
Metamerism
D
Tautomerism
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Geometric
Concept:

Isomerism arising from the restricted rotation of a carbon-carbon double bond, leading to different spatial arrangements of attached groups, is called geometric isomerism.

Solution:

  • The carbon double bond (\( \text{C=C} \)) is rigid and prevents free rotation of the atoms attached to it.


  • If identical groups are locked on the same side of the double bond, it is the cis-isomer.


  • If identical groups are locked on opposite sides, it is the trans-isomer.


  • This specific phenomenon is definitively known as geometric (cis-trans) isomerism.


Why other options are incorrect:

Chain, metamerism, and tautomerism are structural isomers that differ in actual bond connectivity, whereas geometric isomers have the exact same structural connectivity but different spatial orientation (stereoisomerism).

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