Final answer:
The equilbrium constant expression for the ionization of HCN with water is determined by writing the balanced chemical equation and representing the ratio of product ions to reactant molecules at equilibrium.
Step-by-step explanation:
The equilibrium constant expression for the ionization of HCN with water is determined by writing the balance chemical equation for the reaction. The balanced equation is:
- HCN(aq) + H2O(l) → H3O+(aq) + CN-(aq)
Based on this equation, the equilibrium constant expression can be written as:
- K = [H3O+][CN-] / [HCN][H2O]
where the square brackets represent the concentration of the respective species. This equation represents the ratio of the concentration of the product ions (H3O+ and CN-) to the concentration of the reactant molecules (HCN and H2O) at equilibrium.