Answer to Question #157885 in Chemistry for Hadi

Question

Calculate solubility of sold caf2

Answer 1

K_sp(CaF₂) = 4.0 × 10⁻¹¹

Solution:

CaF₂(s) ⇌ Ca²⁺(aq) + 2F^–(aq)

The K_sp expression for CaF₂(s) is:

K_sp = [Ca²⁺][F^–]² = 4.0×10⁻¹¹

ICE Table:

Substitute the equilibrium concentration values from the table into the K_sp expression: 

[Ca²⁺][F^–]² = [ x ] × [ 2x ]² = 4x³ = K_sp

Substitute in the K_sp value to solve for x, the molar solubiltity. 

4x³ = 4.0×10⁻¹¹

x³ = 1.0×10⁻¹¹

x = 2.15×10⁻⁴ M

Answer: The molar solubiltity of CaF₂(s) is 2.15×10⁻⁴ M.