Question

iron(ii) fluoride (fef₂) partially dissolves in water with the equation fef₂ ⇌ fe²⁺ (aq) + 2f⁻ (aq). calculate the solubility of fef₂ in water by using 2.36 × 10⁻⁶ as the solubility product.

Explanation:

Step1: Definir la expresión para \( K_{sp} \)

Para \( FeF_{2}(s)
ightleftharpoons Fe^{2 +}(aq)+2F^{-}(aq) \), \( K_{sp}=[Fe^{2 +}][F^{-}]^{2} \). Sea la solubilidad \( s \), entonces \( [Fe^{2 +}]=s \) y \( [F^{-}]=2s \).

Step2: Sustituir en la ecuación de \( K_{sp} \)

\( K_{sp}=s\times(2s)^{2}=4s^{3} \). Dado \( K_{sp} = 2.36\times10^{-6} \), entonces \( 4s^{3}=2.36\times10^{-6} \).

Step3: Resolver para \( s \)

\( s^{3}=\frac{2.36\times10^{-6}}{4}=5.9\times10^{-7} \), \( s=\sqrt[3]{5.9\times10^{-7}} \approx 8.39\times10^{-3}\,M \).

Answer:

\( 8.39\times 10^{-3}M \)