Answer:
Pentane or 2,2-dimethylbutane
Explanation:
I've numbered the isomeric hexanes from 1 to 5 and labelled the sets of equivalent hydrogens.
The results are
Isomer 1— three sets of equivalent hydrogens
Isomer 2— five sets of equivalent hydrogens
Isomer 3— four sets of equivalent hydrogens
Isomer 4— two sets of equivalent hydrogens
Isomer 5— three sets of equivalent hydrogens
Each set will give one monochloro substitution product.
4 = A. Two monochloro isomers.
2 = B. Five monochloro isomers.
3 = C. Four monochloro isomers.
Isomers 1 and 5 each give three monochloro isomers.
Thus, we cannot assign Structure D definitively.
D is either pentane or 2,2-dimethylbutane.
