Consider the following pairs of structures and identify the relationship between them by describing them as representing enantiomers, diastereomers, constitutional isomers, or two molecules of the same compound.

a) same compound. b) enantiomers. c) diastereomers. d) same compound. e) same compound. f) constitutional isomers. g) diastereomers. h) enantiomers. i) same compound j) enantiomers. k) diastereomers. l) same compound. m) diastereomers. n) constitutional isomers. o) diastereomers. p) same compound. q) same compound.

Explanation:

Enantiomers are compounds are compounds containing chiral centers which are non-superimposable and mirror images such as the compounds in (b), (h), and (j). Diastereomers on the other hand are compounds that containing chiral centers that are non-superimposable but are not mirror images such as the compounds in (c), (g), (k), (m), and (o). Contrarily, constitutional isomers are compounds having the same molecular formula but different connectivity. To check if two molecules are constitutional isomers, the best option is to count the total number of each atom in both molecules and check how the atoms in the molecules are arranged such as the compounds in (f) and (n). The rest are the same compounds.