Answer to Question #170691 in Chemistry for Hyeri

Question

What is the hydronium-ion concentration of a 0.01 F solution of H2CO3 if only the primary ionization reaction is considered.

Answer 1

The dissociation occurs as follows:

H₂CO₃ + H₂O = H₃O⁺ + HCO₃^-

According to the expression:

Ka = [H₃O⁺] [HCO₃^-] / [H₂CO₃]

As Ka₂ = 2.5 × 10^-4, the hydronium-ion concentration equals:

[H₃O⁺] × [H₂CO₃] = Ka / [HCO₃^-] = 0.01 F × 2.5 × 10^-4 = 2.5 × 10^-6

[H₃O⁺]² = 2.5 × 10^-6

[H₃O⁺] = 0.0016 F

Answer: 0.0016 F