Question

Among the following, the weakest bronsted base is:

• A. $F^{-}$
• B. $C{l}^{-}$
• C. $B{r}^{-}$
• D. $I^{-}$

Answer 1

The correct option is D $I^{-}$

According to this theory, an acid is a proton donor and a base is a proton acceptor. Every strong Bronsted acid has a weak conjugate base and every strong base has a weak conjugate acid. The acidity increases in halogen group atoms,

$HF<HCl<HBr<HI$.

So, $HI$ is highly acidic and their conjugate bases decrease in order $F^{-}>C{l}^{-}>B{r}^{-}>I^{-}$.