Calculate the pH of a 0.60 M H₂SO₃,solution that has the stepwise dissociation constants K_a1 = 1.5 × 10^-2 and K_a2 = 6.3 × 10^-⁸. A) 1.02 B) 1.06 C) 1.82 D) 2.04

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The correct answer is A because the pH of a 0.60 M H2SO3 solution that has the stepwise dissociation constants Ka1 = 1.5 × 10-2 and Ka2 = 6.3 × 10-8 is 1.02. This can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]), where pKa is the negative logarithm of the dissociation constant, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the acid. For the first dissociation step, pKa1 = -log(1.5 × 10-2) = 1.82, and for the second dissociation step, pKa2 = -log(6.3 × 10-8) = 7.20. Since the concentration of H2SO3 is much greater than the concentration of HSO3- and SO32-, we can assume that [HA] >> [A-] and simplify the equation to pH ≈ pKa1 = 1.82.

Calculate the PH of a 0