Question

Rank the following species in order of decreasing nucleophilicity in a polar protic solvent `("most"to" least nucleophilic"):`
`(I) CH_(3)CH_(2)CH_(2)O^(-)`" " `(II) CH_(3)CH_(2)CH_(2)S^(-)` `(III) " "CH_(3)CH_(2)overset(O)overset(||)C-O^(-)`
A. 2gt1gt3
B. 2gt3gt1
C. 1gt2gt3
D. 3gt1gt2

Answer 1

Correct Answer - D
`CH_(3)CH_(2)CH_(2)S^(-)(2)` is the strongest nucleophile since S is placed below O in the same group
`CH_(3)CH_(2)-overset(O)overset(|)(C)-O^(-)(3)` has an electrons withdrawing carbonyl group. Therefore, it is a weaker nucleophile than `CH_(3)C H_(2)CH_(2)O^(-)(1)` which does not have any such group.