Which is a stronger base in aqueous solution, IO- or IO3-? Explain.

Answer 1

Look at the acids.
HIO3 --strong acid
HIO -- weak acid.

Now look at the conjugate bases.
HIO3 ==> H^+ + IO3^-
HIO3 is strong acid. IO3^- is the conjugate base and it is WEAK since HIO3 is strong.

HIO ==> H^+ + IO^-
HIO is a weak acid. IO^- is the conjugate base and it is STRONG because HIO is weak.