Question

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

• A. $HClO_3$
• B. $HClO_2$
• C. $HOCl$
• D. $HOBr$

Answer 1

Answer: (A)

$HClO_3$

Answer 2

$\because$ Higher be the oxidation number of central atom in oxo-acids, more strongly it behave as Bronsted-acid.
Oxidation number for $Cl$ in $HClO _{3} \rightarrow+5$
Oxidation number for $Cl$ in $HClO _{2} \rightarrow+3$
Oxidation number for $Cl$ in $HClO \rightarrow+1$
Oxidation number for $Cl$ in $HBrO \rightarrow+1$
Hence, $HClO _{3}$ is the strongest Bronsted acid in aqueous solution.