The fluoride ion is the conjugate base of the weak acid hydrofluoric acid. The value of Kb for F-, is 1.39*10-11. Write the equation for the reaction that goes with this equilibrium constant.

F⁻ (aq) + H₂O (l) ⇄ HF (aq) + OH⁻ (aq)

Explanation:

According to Brönsted-Lowry acid-base theory, an acid is a substance that donates H⁺ ions. In this sense, hydrofluoric acid is an acid according to the following equation.

HF (aq) + H₂O (l) ⇄ F⁻ (aq) + H₃O⁺ (aq)

According to Brönsted-Lowry acid-base theory, a base is a substance that accepts H⁺ ions. In this sense, the fluoride ion is a base according to the following equation.

F⁻ (aq) + H₂O (l) ⇄ HF (aq) + OH⁻ (aq)

The equilibrium constant for this reaction is Kb = 1.39 * 10⁻¹¹.