Question

Which will have enantiomers:
1) n-butyl chloride
2) ter-butyl chloride
3) sec-butyl chloride
4) iso-butyl chloride

Answer 1

Hint: The enantiomers are the molecules that have a chiral center and the two molecules are the non-superimposable mirror images of each other. One can draw the structure given in the options and see which structure follows the rules to show the enantiomer presence.

Complete answer:
1) First of all we will see the concept of enantiomer and which molecules can give the enantiomer. The first requirement to show enantiomerism in a molecule is that it must have at least one chiral center in the structure. The second requirement is that the two molecules must have been the non-superimposable mirror images of each other which mean only one atom or group is rotated by a total one-eighty degree angle than the other structure.
2) Now that we have understood the concept of enantiomers now let's analyze each structure one by one and see which can give the enantiomers. The structure n-butyl chloride does not possess any chiral center carbon in its structure which means it can't give the enantiomer. Hence, this option is an incorrect choice.
3) The structure ter-butyl chloride does not possess any chiral center carbon as there is more than one same group that is methyl group is attached to one same carbon which means it can’t give enantiomers. Hence, this option is an incorrect choice.
4) The structure sec-butyl chloride possesses the chiral center at the second carbon where the chlorine atoms are attached which means it gives the enantiomer. Hence, this option is the correct choice.
5) The structure iso-butyl chloride does not possess any chiral center as there is more than one same group that is present on the same carbon which is methyl group which means it can’t give enantiomers. Hence, this option is an incorrect choice.
6) The diagrammatic representation of the enantiomers is as below,

7) Therefore, the structure sec-butyl chloride gives the enantiomers

So, the correct answer is Option C.

Note: The chiral carbon center is the carbon atom which is attached to four different atoms or molecules or groups. The enantiomer is the mirror images of each other which mean if a group is attached above the plane on the chiral center it will go below the plane in other enantiomeric structure.