Read the statement and study the reaction.

NaCN dissociates into Na+ and CN– ions in water (H2O).

CN– hydrolyzes water according to following reaction:

CN– + H2O ⇌ HCN + OH–

A sample solution has 0.051 M of CN– ions, and the pH of the solution is 10.96. What is the equilibrium constant for this reaction?

9.7 × 10–6
6.22 × 10–6
1.63 × 10–5
3.10 × 10–5