Question

Write chemical equations and corresponding equilibrium expressions for each of the two ionization steps of carbonic acid.

Answer 1

H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq) K₁ = [H⁺][HCO₃⁻]/[H₂CO₃]

HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq) K₂ = [H⁺][CO₃²⁻]/[HCO₃⁻]

Step-by-step explanation:

Let's consider the equation for the first step of the ionization of carbonic acid.

H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)

The first ionization constant is:

K₁ = [H⁺][HCO₃⁻]/[H₂CO₃]

Let's consider the equation for the second step of the ionization of carbonic acid.

HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)

The second ionization constant is:

K₂ = [H⁺][CO₃²⁻]/[HCO₃⁻]