Question

Which of the following is strongest Bronsted base?

• A. $Cl{O}^{-}$
• B. $Cl{O}_2^{-}$
• C. $Cl{O}_3^{-}$
• D. $Cl{O}_4^{-}$

Answer 1

Answer: (A)

$HCl{O}_4$ is the strongest acid among $HClO,HCl{O}_2,HCl{O}_3$

and $HCl{O}_4$ as more the number of oxygen atoms attached,

more is the acidity of the molecule order of acidity is:

$HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$

So the conjugate base order will be just the reverse:

$Cl{O}^{-}>Cl{O}_2^{-}>Cl{O}_2^{-}>Cl{O}_3{}^{-}>Cl{O}_4^{-}$