Answer:
Explanation:
The first step is to <u>know where we have the double bond</u> in each molecule:
a)
b)
c)
d)
e)
f)
Now, we have to keep in mind that we can have isomers Cis or Trans <u>arround the double bond</u>. The first step is to identify the <u>most important group</u> in each carbon in the double bond. If these groups are in the <u>same side</u> we will have a Cis isomer, if these groups are in <u>opposite sides</u> we will have a trans isomer.
The next step is to check one by one, so:
a)
In this molecule in the right carbon in the double bond, we have two hydrogens. So <u>we can not choose the most important one</u> in this carbon because we have two identical substituents in the same carbon. So, it's not possible to have Cis/Trans Isomers on this molecule.
b)
In b molecule, we have the same situation, but in this case, is in the left carbon. In the left carbon, we will have <u>2 methyl groups</u>. So, we can not choose the most important group on this carbon and therefore we can not have Cis/Trans Isomers.
c)
In this molecule on the left carbon, we have the <u>ethyl group</u> as the most important one. In the right carbon is the <u>methyl group</u>. So, when the ethyl and the methyl have opposite orientations we will have the Trans isomer, when we have the same orientation we will have the Cis isomer.
d)
In d molecule we have the <u>same substituents</u> on the left carbon, we have 2 methyl groups. So, it's not possible to have Cis/Trans isomers.
e)
In e molecule, we the most important substituent in the left carbon between the Cl and H <u>is the Cl</u>. The same behavior is repeated in the right carbon, where <u>we have the C</u>l as the most important substituent. Therefore we can have the Cis/Trans isomers.
d)
For d molecule, we will have a similar situation than e molecule. On the left carbon, we will have as more important substituent the <u>Br atom</u>. In the right carbon, <u>we will have Cl</u> as the more important one. So, we can have the Cis/Trans isomers.
<u>To further explanations see the picture attached</u>
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