Question

Two geometrical isomers are given by the following compound
A. Ethylidene bromide
B. Acetylene tetrachloride
C. Acetylene tetrabromide
D. Acetylene dibromide

Answer 1

Hint: The chemical which has the same chemical formula and exists in different forms is called isomers. The compounds or chemicals which have a double bond in its structure generally show geometrical isomerism.

Complete step by step answer:
- In the question it is asked which molecules among the given options will show two geometrical isomers.
- To find it we have to draw each and every structure of the compound given in the options.
- Coming to option A, Ethylidiene bromide.
- The structure of ethylidene bromide is as follows:

- In the above structure we can clearly see that there is no double bond present in it.
- Therefore option A does not show that geometrical isomerism.
- Coming to option B, acetylene tetrachloride.
- The structure of acetylene tetrachloride is as follows.

- In the structure of option B, there is no double bond.
- Therefore acetylene tetrachloride is not going to exhibit geometrical isomerism.
- Coming to option C, Acetylene tetrabromide.
- The structure of Acetylene tetrabromide is as follows:

- In the structure of option C, there is no double bond.
- Therefore acetylene tetrabromide is not going to exhibit geometrical isomerism.
- Coming to option D, Acetylene dibromide.
- The structure of Acetylene dibromide is as follows.

 - In the structure of the acetylene dibromide there is a presence of double bond.
- Therefore acetylene dibromide is going to show geometrical isomerism.
- The geometrical isomerism of the compound acetylene dibromide is as follows.

Therefore option D is correct.

Note: The compound which exhibits geometrical isomerism shows two types of isomers. The two types of geometrical isomers are cis and trans. Trans form of a compound is more stable then the cis form because of the less steric hindrance.