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Why is cis–trans isomerism common in alkenes?

Answer 1

Cis-trans isomerism is common in alkenes because there is restricted rotation about double bonds.

For example, an alkene such as but-2-ene has two different groups on each alkene carbon.

It can exist as #E-Z# isomers that differ in the positions of the substituents on the double-bonded atoms.

The double bond prevents rotation about the C=C axis.

So the molecule exists as two isomers, with substituents on the same side (cis) or on the opposite side (trans) of the double bond.

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Answer 2

Delilah Anderson

Cis-trans isomerism is common in alkenes because of restricted rotation around the carbon-carbon double bond, leading to different spatial arrangements of substituent groups. This restricted rotation allows for two distinct arrangements of atoms or groups around the double bond, resulting in cis and trans isomers.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.