Question

How many aromatic isomers of di-bromobenzene exist?
A. 2
B. 3
C. 1
D. 4

Answer 1

Hint: In chemistry carbon is a very versatile and important element. Its tetravalent nature allows it to bond with up to four elements at a time. Carbon can form chains of compounds, this property is called catenation.

Complete step by step answer:
The compound of carbon is tetravalent and thus can form many compounds of various properties. Carbon has a unique property of catenation, in that the carbon atom can form large chains of carbon atoms which are stable too. This property allows the carbon atom to form a chain and cyclic structures that exhibit large and varied properties.
One of the most popular examples of such property is benzene which is a six-membered ring. This compound also shows a property of aromaticity. It states that the electrons inside the benzene atom are not stationary but are continuously resonating. Resonance is the property which explains the property that the electrons in a compound are not stable by their stationary nature but are actually in continuous motion from one place to another within the atom.
The compound di-bromobenzene resonated into three forms which can be written as follows

So we can see that the number of aromatic isomers of di-bromobenzene exists is 3.

so, the correct answer to the above question is B.

Note: Apart from the resonance effect, various other effects are operating in the organic compounds.
The inductive effect is the effect due to the transmission of the inequality in the sharing of the electron during the bonding process through the chain of atoms in the molecule. It may be the reason for a permanent dipole in the compound due to this effect.
The electron-withdrawing effect of the chain is termed negative inductive effect and the electron-donating effect is termed as positive inductive effect.