Which is the stronger acid in each of the following pair #H_2SeO_3# or #H_2SeO_4#?

1 Answer
Jul 31, 2015

#"H"_2"SeO"_4# is the stronger acid.

Explanation:

For oxyacids with the same central atom, the acidity increases as the number of atoms bonded to the central atom increases.

Thus, we predict that #"H"_2"SeO"_4# should be a stronger acid than #"H"_2"SeO"_3#.

This is confirmed by their #K_"a"# values .

#"H"_2"SeO"_4# has #K_a >1#, while #"H"_2"SeO"_3# has #K_a = 2.3 × 10^-3#.