2-bromo-1-chloro-4-nitrobenzene is being synthesized in following sequence:
Step 1: Chlorination of Benzene:
This is Halogenation reaction of benzene. In this step benzene is reacted with Chlorine gas in the presence of lewis acid (i.e. FeCl₃). This results in the formation of Chlorobenzene as shown in red step below.
Step 2: Nitration of Chlorobenzene:
The chlorine atom on benzene has a ortho para directing effect. Therefore, the nitration of chlorobenzene will yield para nitro chlorobenzene as shown in blue step below.
Step 3: Bromination of 1-chloro-4-nitrobenzene:
In this step bromination is done by reacting bromine in the presence of lewis acid. The chlorine being ortho para directing in nature and nitro group being meta directing in nature will direct the incoming Br⁺ (electrophile) to the desired location. Hence, 2-bromo-1-chloro-4-nitrobenzene is synthesized in good yield.
Answer:
2. carbon
Explanation:
carbon should be the answer
<u>Answer:</u>
NO ---> N +2 and O -2
<u>Explanation:</u>
Oxidation numbers are assigned to the elements of a compound to keep a track of the number of electrons each atom has.
Here we have a compound NO (Nitrogen Oxide). The Nitrogen is assigned an oxidation number of +2 while Oxygen in this compound is assigned an oxidation number of -2.
So the algebraic sum of the oxidation numbers of the elements in the compound NO is equal to zero.