Calculate the PH of a Sulfurous Acid Buffer Prepared from 0.010

Essay

Calculate the pH of a sulfurous acid buffer prepared from 0.010 M NaHSO₃ and 0.030 M Na₂SO₃.K_a1 = 1.39 × 10⁻² and K_a2 = 6.73 × 10⁻⁸ for sulfurous acid.
Ionic strength (,M)
Ion
0.001
0.005
0.01
0.05
0.1
Charge =  1
Activity coefficient ()
Na⁺,0.964
0.928
0.902
0.82
0.775
Charge =  2
Activity coefficient ()0.867
0.742
0.665
0.455
0.37