Chromic acid is a diprotic acid: H₂CrO₄(aq) $\leftrightarrows$ HCrO₄^-(aq) + H⁺(aq) K_a1 = 3.55
HCrO₄^-(aq) $\leftrightarrows$ CrO₄²^-(aq) + H⁺(aq) K_a2 = 3.36 $\times$ 10^-7
Calculate the theoretical value of the equilibrium constant for 2 HCrO₄^-(aq) $\leftrightarrows$ H₂CrO₄(aq) + CrO₄^2-(aq) .

Question

Chromic acid is a diprotic acid: H₂CrO₄(aq)

\leftrightarrows

HCrO₄^-(aq) + H⁺(aq) K_a1 = 3.55
HCrO₄^-(aq)

\leftrightarrows

CrO₄²^-(aq) + H⁺(aq) K_a2 = 3.36

\times

10^-7
Calculate the theoretical value of the equilibrium constant for 2 HCrO₄^-(aq)

\leftrightarrows

H₂CrO₄(aq) + CrO₄^2-(aq) .

Quizplus · Accepted Answer

The theoretical value of the equilibrium constant can be determined by multiplying the equilibrium constants of the two reactions. The equilibrium constant of the first reaction is given as K_a1 = 3.55, and the equilibrium constant of the second reaction is given as K_a2 = 3.36. Therefore, the theoretical value of the equilibrium constant for the overall reaction is: K_a1 × K_a2 = (3.55) × (3.36) = 11.918 ≈ 9.46 Thus, the best choice is C.

Chromic Acid Is a Diprotic Acid: H2CrO4(aq) ⇆\leftrightarrows⇆ HCrO4-(aq)+ H+(aq)Ka1 = 3

Chromic Acid Is a Diprotic Acid: H₂CrO₄(aq) $\leftrightarrows$ HCrO₄^-(aq)+ H⁺(aq)K_a1 = 3