Question

Which is the strongest acid in the following?

• A. $HCl{O}_4$
• B. $H_{2}S{O}_3$
• C. $H_{2}S{O}_4$
• D. $HCl{O}_3$

Answer 1

The correct option is A $HCl{O}_4$

$H\stackrel{7}{\underset{–}{Cl}}{O}_4$ with highest oxidation number and its conjugate base is resonance stabilized, hence it is most acidic. Cl is more electronegative than S.