Question

Consider a disubstituted aromatic compound. The parent name is benzene and there is a chloro and bromo substituent. Disubstituted benzenes can be described using the terms ortho, meta and para, depending on their relative distance from each other. The terms are often just abbreviated as o, m and p. In addition, the IUPAC name can use locant numbers instead of the descriptor. Br
Select the correct names for the structure.
1. 1-bromo-3-chlorobenzene
2. 3-bromo-1-chlorobenzene
3. meta-bromochlorobenzene
4. o-bromochlorobenzene
5. ortho-bromochlorobenzene
6. m-bromochlorobenzene

Answer 1

Answer:The correct names for the structure are:

--> 1. 1-bromo-3-chlorobenzene.

--> 3. meta-bromochlorobenzene.

--> 6. m-bromochlorobenzene.

Explanation:

Benzene is the simplest member of the aromatic hydrocarbons. It has a ring structure consisting of six carbon and six hydrogen atoms. This equally means that a benzene can have up to six substituents. One of the chemical properties is that benzene and other members of its series undergo substitution reaction whereby one or more of its six hydrogen atoms is replaced by monoatomic reagents.

Disubstituted benzene consists of two substituents which are described based on either numerical locants or specific words for the three possible forms.

The numerical locant method are used the same naming substitutes of other hydrocarbons. From the question, the numerical locant method was derived through using the following steps:

--> the functional group is benzene

--> there are two substituents which includes bromine( written as bromo) and chlorine ( written as chloro)

--> while placing the number, it's done alphabetically ('1-bromo' comes before '3-chloro') in a clockwise manner. This is to give chorine the lowest locant number.

The second naming method for a disubstituted benzene is the the ortho-, meta-, para- (or their singel letter equivalent) nomenclature method. This is only used for benzene structures.

--> ortho or O : this is used when the substituents are close to each other in the benzene ring.

--> meta or (m) : This is used when the substituents are separated by one carbon in the benzene ring.

--> para or (p): This is used when the substituents are across each other in the benzene ring

From the question, the bromine substituent is separated from the chlorine by one carbon atom, therefore it's meta-bromochlorobenzene or m-bromochlorobenzene.