Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

With trans-but-2-ene, the product of ${\mathrm{Br}}_2$ addition is optically inactive due to the formation of symmetric meso compounds.

In general, for symmetrical alkenes and symmetrical reagents, the addition takes place as: $\begin{array}{c}\text{ cis-alkene }+\text{ syn-addition }\to \text{ meso }\\ \text{ trans-alkene }+\text{ syn-addition }\to \text{ racemic }\\ \text{ cis-alkene }+\text{ anti-addition }\to \text{ racemic }\\ \text{ trans-alkene }+\text{ anti-addition }\to \text{ meso }\end{array}$