Which of the following is an aromatic compound?

What is isomerism? Which are the types of isomerism?

The total number of stereoisomers possible for the given compound $1,3,5$-tribromocyclohexane is:

Consider the sets $I$,$II$,and $III$. Identify the set$(s)$ which is (are) correctly matched.
$I$. $\text{Staggered ethane} > \text{eclipsed ethane} \dots \dots \dots \text{torsional strain}$.
$II$. $2, 2-\text{Dimethylbutane} > 2-\text{methylpentane} \dots \dots \dots \text{boiling point}$.
$III$. $cis-\text{but}-2-\text{ene} > trans-\text{but}-2-\text{ene} \dots \dots \dots \text{dipole moment}$.

Which of the following pairs of compounds are not positional isomers?

The total number of stereoisomers possible for the following compound is: