Find out how many stereoisomers are there for the molecule given below?

 

What is the relationship between the compounds shown below?

How are these compounds related?

How many stereoisomers are possible for this molecule?

Which of the following molecules is chiral?

$\mathrm{I}$. Trans$-1-$chloro$-2-$methyl cyclopropane
$\mathrm{II}$. Cis$-1-$chloro$-2-$methyl cyclopropane
$\mathrm{III}$. $1-$chloro$-1-$methyl cyclopropane
$\mathrm{IV}$. Cis$-1,2-$dichlorocyclopropane

The specific rotation of pure laevorotatory $2-$butanol is $-21°$. A pure liquid $2-$butanol has a specific rotation of $+12°$ under identical conditions. Enantiomeric composition of this liquid is