Question

The IUPAC name of the insecticide lindane is:
(A) Dichlorodiphenyltrichloroethane
(B) Benzene hexachloride
(C) Hexachloran
(D) 1,2,3.4,5,6-hexachlorocyclohexane

Answer 1

Hint: IUPAC nomenclature is used to make an international standard of naming molecules to help in communication. By this IUPAC nomenclature each structure is given a unique name and structure.

Complete step by step solution:
In IUPAC nomenclature, the root word is basically the number of total carbons in a longest chain of that compound.

No. of carbons	Root word
1	meth
2	eth
3	prop
4	but
5	pent

… and so on.
The primary suffix is basically used to differentiate between the saturated compounds( Alkanes) and unsaturated compounds (Alkene and Alkynes).

Compound	Suffix
Alkane	ane
Alkene	Ene
Alkyne	Yne

If there are more than one suffix. Then one of those suffixes is considered a secondary suffix.
Example: Methanol (Alkanol) , here ‘ol’ is a secondary suffix.
The primary prefixes are basically used to differentiate between cyclic compound and noncyclic or chain compound. For cyclic compound prefix s ‘cyclo’ . If there are any side chains or groups are present then secondary prefixes like ‘methyl’, ‘ethyl’ are used.
The structure of lindane is ,
 
The IUPAC name of lindane is gamma-hexachlorocyclohexane. It is also called benzene hexachloride.
In this structure two chlorine atom are cis to each other are at gamma position that is why gamma is written in the IUPAC name.
It is a cyclic compound so “cyclo” prefix is used. Six carbon is present in the ring so “hex” is the word root. And “ane” is used as the primary suffix.
There are six chlorine atoms present that is why “hexa chloro” is added in the name.

Therefore, the correct option is B.

Note: In agricultural science lindane is used as an insecticide on fruit, vegetables etc. It has uses in pharmaceutical treatment too. primary prefixes are used to indicate the origin of the compound in IUPAC nomenclature and suffixes are used to indicate the functional group of that molecule.