Which of the following compounds are capable of cis–trans isomerism? (a) 1-Hexene (b) 2-Hexene (c) 3-Hexene

Cis-trans isomerism, also known as geometric isomerism, occurs in compounds with restricted rotation around a double bond or a ring structure. In this type of isomerism, the spatial arrangement of substituents differs, leading to distinct physical and chemical properties. The 'cis' configuration has similar groups on the same side, while the 'trans' configuration has them on opposite sides.

Alkenes are hydrocarbons that contain at least one carbon-carbon double bond (C=C). The presence of this double bond is crucial for cis-trans isomerism, as it restricts the rotation of the carbon atoms involved. The position of substituents around the double bond determines whether the compound can exhibit geometric isomerism.

For a compound to exhibit cis-trans isomerism, it must have two different substituents attached to each carbon of the double bond. If both carbons in the double bond have identical substituents, cis-trans isomerism cannot occur. Therefore, analyzing the structure of the given compounds is essential to determine their capability for geometric isomerism.