Question

Of the following compounds, which one is the strongest Bronsted acid in aqueous solution?

• A. $HCl{O}_3$
• B. $HCl{O}_2$
• C. $HOCl$
• D. $HOBr$

Answer 1

Answer: (A)

$\because$ Higher be the oxidation number of central atom in oxo-acids, more strongly it behave as Bronsted-acid.
Oxidation number for $Cl$ in $HCl{O}_3\to +5$
Oxidation number for $Cl$ in $HCl{O}_2\to +3$
Oxidation number for $Cl$ in $HClO\to +1$
Oxidation number for $Cl$ in $HBrO\to +1$
Hence, $HCl{O}_3$ is the strongest Bronsted acid in aqueous solution.