Of the following, which is the weakest acid?

Question

A. H₂SO₃ 

B. H₂SO₄ 

C. H₂SeO₄ 

D. H₂SO₃^-

E. The acid strength of all of the above is the same.

Answer 1

Look up the Ka for each and the one that has the lowest Ka would be the weakest. Remember that 1x10^-7 is lower than 1x10^-5 for example.