Answer to Question #25163 in Physical Chemistry for ahmed

Question

What are the equilibrium concentrations of H2SO3, H+, HSO3−, and SO32−in a 0.050 M solution of sulfurous acid H2SO3 at 25 oC? For H2SO3 at 25 oC, Ka1 = 1.5×10−2 and Ka2 = 1.0×10−7

Answer 1

Concentration of H₂SO₃ is 0.050 M
Concentration of HSO₃^- is next:
K₁=[H⁺][HSO₃^-]/[H₂SO₄][H⁺]=[HSO₃^-]
K₁=[HSO₃^-]^2/[H₂SO₄]
[HSO₃^-]^2=K₁*[H₂SO₄]
[HSO₃^-]=(K₁*[H₂SO₄])^1/2
[HSO₃^-]=(0.015*0.05)^1/2=2.77*10^-2
The same with [SO₄^2-]
[SO₃^2-]=(K₂*[SO₄^2-])^1/2 = 5.26*10^-5
[H⁺] is the sum of this two results