Question

Which of the following compounds will show cis-trans isomerism?

• A. $(C{H}_3{)}_{2}C=CH{C}_2{H}_5$
• B. $H_{2}C=CC{l}_2$
• C. $C{H}_{3}HC=CClC{H}_3$
• D. $HClC=C{H}_2$

Answer 1

Answer: (C)

$C{H}_{3}HC=CClC{H}_3$

A. $(C{H}_3{)}_{2}C=CH{C}_2{H}_5$ has two methyl groups attached to the same carbon of the double bond so not possible.

B. $H_{2}C=CC{l}_2$ has two chlorine atoms attached to the same carbon of the double bond. The other carbon has two hydrogen atoms attached to it. So it is not possible.

C. $C{H}_{3}HC=CClC{H}_3$ has different groups attached to both carbons of the double bond.

D. $HClC=C{H}_2$ has two hydrogen atoms attached to the same carbon of the double bond.

Since all compounds have the same groups attached to double bonded carbon atom except in 2-Chlorobut-2-ene, thus only 2-Chlorobut-2-ene exhibit cis-trans isomerism.