Will a precipitate of magnesium fluoride form when 300.mL of 1.1 * 10^-3 M MgCl₂ are added to 500.mL of 1.2 * 10^-3 M NaF? [K_sp (MgF₂)= 6.9 * 10^-9]

Question

Quizplus · Accepted Answer

The reaction quotient Q is calculated using the concentrations of Mg²⁺ and F^- ions in the mixed solution. After mixing, [Mg²⁺] = (0.3 L * 1.1 * 10^-3 M) / 0.8 L = 4.125 * 10^-4 M and [F^-] = (0.5 L * 1.2 * 10^-3 M) / 0.8 L = 7.5 * 10^-4 M. Q = [Mg²⁺][F^-]² = (4.125 * 10^-4)(7.5 * 10^-4)² = 2.32 * 10^-10, which is less than K_sp (6.9 * 10^-9), so no precipitate forms.

Will a Precipitate of Magnesium Fluoride Form When 300