The acid-dissociation constant of hydrocyanic acid (HCN)at 25.0°C is 4.9 × 10^-¹⁰.What is the pH of an aqueous solution of 0.080 M sodium cyanide (NaCN)? A)11.11 B)2.89 C)1.3 × 10^-3 D)7.8 × 10^-12 E)3.9 × 10^-11

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Sodium cyanide (NaCN) is a salt that dissociates into Na⁺ and CN⁻ ions. CN⁻ is the conjugate base of the weak acid HCN. The pH of the solution can be calculated using the base dissociation constant (Kb) of CN⁻, which is derived from the relation Kw = Ka × Kb. Given Ka for HCN, Kb can be calculated, and then the pH can be determined from the concentration of OH⁻ ions produced by CN⁻ in solution. The calculated pH is approximately 11.11.

The Acid-Dissociation Constant of Hydrocyanic Acid (HCN)at 25