Question

Draw cis and trans isomers of the following compounds. Also write the IUPAC names:
A. $CHCl=CHCl$
B. ${{C}_{2}}{{H}_{5}}CC{{H}_{3}}=CC{{H}_{3}}{{C}_{2}}{{H}_{5}}$

Answer 1

cis isomers are the isomers where substituents are on the same side whereas trans isomers are the isomers where susbtituents are on the opposite side of each other. Isomers have identical molecular mass.

Complete step by step answer:
Cis and trans isomers are the geometric isomers which are used in organic chemistry. Cis isomers are defined as the isomers where the substituent groups are oriented in the same direction. Trans isomers are defined as the isomers where the substituent groups are oriented in the opposite direction of each other.
Let us now see the following structures.
1. Cis and trans isomers $CHCl=CHCl$ can be represented as

2. Cis and trans isomers ${{C}_{2}}{{H}_{5}}CC{{H}_{3}}=CC{{H}_{3}}{{C}_{2}}{{H}_{5}}$ can be represented as

Additional information:

To identify cis and trans isomers, if two substituent groups are attached on the same side of the double bond then it is known as cis isomer and if two substituent groups are attached on the opposite side of the double bond then it is known as trans isomer.
The cis isomers are polar molecules whereas the trans isomers are non-polar molecules. In cis isomers, the substituent groups are on the same side, therefore, one side of the molecule will have slightly positive charge, whereas other side will have slightly negative charge, which makes the molecule polar.
The trans isomers are more stable than cis isomers because of the steric hindrance on cis isomers.

Note: cis and trans isomers are the geometric isomers in which trans isomers are much more stable than the cis isomers becuase in trans isomers there is no steric hinderance of the substituent group whereas in cis isomers they is a steric hinderance of the substituent group.