Aluminumcan form two complex ions with fluoride, AlF63–(Kf= 2.4x10^4), which forms in solutions with [F–] > 1.5M and AlF4–(Kf= 2.0x10^8), which forms when [F–] is between 0.5 M and 1.5M. 100 mL of 0.20 M Al(NO3)3is combined with 500 mL of a pH 4.25 HF/NaF buffer (total concentration of 2.0M). Given that the sodium salt of the complex ion has a solubility of 0.042 g/100 mL, will the sodium salt precipitate from the equilibrium mixture? Why or why not? If AlF63–forms, the sodium salt would be Na3AlF6; if AlF4–forms, the sodium salt would be NaAlF4.

Aluminumcan form two complex ions with fluoride, AlF63–(Kf= 2.4x10^4), which forms in solutions with [F–] > 1.5M and AlF4–(Kf= 2.0x10^8), which forms when [F–] is between 0.5 M and 1.5M. 100 mL of 0.20 M Al(NO3)3is combined with 500 mL of a pH 4.25 HF/NaF buffer (total concentration of 2.0M).

Given that the sodium salt of the complex ion has a solubility of 0.042 g/100 mL, will the sodium salt precipitate from the equilibrium mixture? Why or why not? If AlF63–forms, the sodium salt would be Na3AlF6; if AlF4–forms, the sodium salt would be NaAlF4.