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Q.
But-$2$-ene exhibits cis-trans-isomerism due
to
AIPMTAIPMT 2000Organic Chemistry – Some Basic Principles and Techniques
Solution:
Due to presence of $> C = C < $ in butene-$2$, it shows restricted rotation. Hence, give two types of arrangements around the space of $ > C = C < $ as cis and trans-forms.