Which is a stronger acid?

Question

Both HA and HB are weakly acidic. The pH values of their potassium salt solutions, NaA and NaB, at equal concentrations are measured to be 7.98 and 11.23. Which acid is stronger, HA or HB, and explain!

Answer 1

If we dissolve KA in solution we get A- + H2O =  HA + H3O + 

the pH = 7.98 so the [H3O+] =  10 ^-7.98 = 1.047 E-08 =[HA]

for the KB solution [H3O+] = 5.88 E-12 =[HB] 

since more of the HA is formed under similar conditions the H is more strongly attached to the anion and HA is the weaker acid

when H2O reacts with B- much less HB is formed and the H is less attached to the anion and the HB would dissociate easier . HB is a stronger acid.