For the following
`(i) I^(-) (ii) Cl^(-) (iii) Br^(-)`
the increasing order of nucleophilicity would be:

Options

A. `I^(-) lt Br^(-) lt Cl^(-)`
B. `Cl^(-) lt Br^(-) lt I^(-)`
C. `I^(-) lt Cl^(-) lt Br^(-)`
D. `Br^(-) lt Cl^(-) lt I^(-)`

Answer

B

Explanation

In polar protic solvents (e.g. water and alcohols, any solvent with ) OH nucleophilicity increases as you go down the periodic table
`F^(-) lt Cl^(-) lt Br^(-) lt I^(-)`
In polar aprotic solvents (e.g. DMSO, acetone) the order is reversed and the most basic nucleophiles are also the most nucleophilic
`I^(-) lt Br^(-) lt Cl^(-) lt F^(-) `