Question

What is the minimum number of carbon atoms required in order to show geometrical isomerism in alkenes.

Answer 1

Positional isomers are constitutional isomers that have the same carbon skeleton and the same functional groups but differ from each other in the location of the functional groups on or in the carbon chain.

Positional isomerism is generally exhibited by alkenes, alkynes, alkyl halides, ketones and alcohols etc.

So, in an alkane chain, it'd require at least 3 carbons.

Example: Propyl bromide (1) and isopropyl bromide (2) are constitutional isomers.

Answer 2

Hey mate,

Here is your answer

Minimum 4 carbon atoms are required for alkenes to show position isomerism( if there is no functional group other than the double bond).