Question

Which one of the following is the correct formula of dichlorodiphenyltrichloroethane?
A.

B.

C.

D.

Answer 1

Hint: Naming of organic compounds in organic chemistry is based on the IUPAC nomenclature. The IUPAC nomenclature follows some set of rules to give the name of the compound. Some compounds are known by the IUPAC name whereas some compounds are popular by their common names. The IUPAC name help in depicting the arrangement of atoms in a compound.

Complete step-by-step answer:The given name in the question is based on IUPAC nomenclature. Hence apply the rules of IUPAC nomenclature and identify the correct structure.
The naming is divided into three parts
-Naming of parent chain which is the chain having maximum number of carbon atoms.
-Naming of functional groups if present any
-Naming of side substituents along with correct identification of position number of these substituents.

In dichlorodiphenyltrichloroethane, ethane represents the parent chain having \[2\] carbon atoms. Thus, named as 'eth'
Dichlorodiphenyl trichloro is the name given to the side substituents. There are two side substituents present
One is chloro which are \[3\] in number hence named trichloro
Other is chlorobenzene. In IUPAC nomenclature, benzene as a substituent is named as phenyl. Dichlorodiphenyl refers to two benzene rings with chlorine. The benzene ring is attached to ethane carbon through its para position.
Option B is incorrect because the chlorine atom is not attached to the benzene ring.
Option C has chlorine on only one benzene ring but it should be on both.
Option D has chlorine on both the rings but there are \[4\] chlorine attached to the parent chain which is incorrect.

Option ‘A’ is correct

Note: ‘ane’ represents alkane where the carbon atoms are connected through a single bond. Ene represents double bond and yne represents triple bond. Meth means one carbon atom in the parent chain. Eth means two, prop means three, but means four and pent means five.