Question

43)

Write a balanced net ionic equation to show why the solubility of MnCO3 (s) increases in the presence of a strong acid and calculate the equilibrium constant for the reaction of this sparingly soluble salt with acid.

Consider only the FIRST STEP in the reaction with strong acid. Use the pull-down boxes to specify states such as (aq) or (s).

K=____

Answer 1

MnCO₃(s) Mn²⁺(aq) + CO₃^2-(aq) K_sp

In presence of strong acid , carbonate ion combines with H⁺ ion and the above equilibrium would shift in forward direction. Hence solubility will increases.

H⁺ ​​​(aq) + CO₃^2-(aq) HCO₃^-(aq) K_eq = 1/K_a2

K_a2 is the second dissociation constant of weak acid, H₂CO₃.

Adding these two equilibrium , we get

MnCO₃(s) + H⁺ (aq) Mn²⁺(aq) + HCO₃^-(aq) K = K_sp/K_a2