How many ions form when 39 grams of calcium fluoride are added to excess water? a. 0.50 mol b. 1.0 mol c. 1.5 mol d. 3.0 mol

c. 1.5 mol

Explanation:

n = mass / molar mass = (39.0 g) / (78.07 g/mol) = 0.499 mol ≅ 0.5 mol.

CaF₂ → Ca⁺² + 2F⁻.

Every 0.1 mole of CaF₂ is ionized to 3 ions (1 ion of Ca⁺² and 2 ions of F⁻).

So, 0.5 mol of CaF₂ will contain (3 x 0.5 mol = 1.5 mol) of ions.

Thus, the right choice is "c. 1.5 mol".