A pair of stereoisomers might be classified in various ways. Which of the following statement are true with respect to pairs of stereoisomers?
(a) They might be configurational isomers
(b) They might be diastereomers
(c) They might be constitutional isomers
(d) They might be tautomers
(e) They might be conformational isomers
(f) They might be enantiomers
(g) They might be positional isomers
a, b, f
Stereoisomers are actually configuration isomers.Thus they can be diastereomers (geometrical/optical) and enantiomers (non superimposable mirror image). Stereoisomers are not constitutional isomers, thus cannot be tautomers and positional isomers.
Conformational isomers deal with bond rotation without change in configuration, thus, stereoisomers cannot be conformational isomers.