Question

Calculate the solubility at 25 °C of CaF2 in pure water and in a 0.0060 M NaF solution. You'll find K. data in the ALEKS Data tab. Round both of your answers to 2 significant digits. solubility in pure water: solubility in 0.0060 M Naf solution: x 6 ?

Answer 1

calcium fluoride (Cafa) is a sparing ly soluble Salt. It dissociates very wearly in solution. with ksp value = 3.9x10ll Solubility of cafe in pure water. The dissociation of care in water can be written as, ICE table Initial, caf(s) f - solid can can tap-can 0 Solid & +25 Changes Eqนนน 55i Arm, - Solids 25 Where, so be the molar Solubility of cafe in Water, à solubility product, • ksp = [ca2+] [f-]" 3.9x10l = Sx (25) 453 = 3.9x18-1 S = 2.1 363 X 109 solar solubilite pure water- water = 2.1363x10 to Now, molar mass of cat=17811 g/mee solubility of cafe in water in g/L 2:13G 3 X164 move 78.1g 1 role 0.01668 GIL

- in Maf. salt. Maf. Solubility Sodium fluoride (Naf) is an ionic It dissociates as, - Nafat) y Nattay t F- (at) 0.0060 0.0060 0.gobo [fo] =0.006om Now, dissociation equilibrium of cafe in ICE table Cafe (s) ca²t can +27 (99) mitial, 0.006 0 Change +25 Naf, Equilibrium - 0.00 60+2s so be the molar AS, solubility of cafe in Car is a sparingly may Naf consider, soluble salt we 0.00 Go + 250.0060 in of solubility product kip = [ calty [AT 3.9x10" = Sx (0.0068) > S = 1.0833x10-6 Solubility in Nag= 1.0833 x 106 in. And solubility cafe decreases due to presence of commorans. Sholar mass of cafe= 78.1 g/mol solubility of care in nar ingil. = 1.0833x66 more, la i = (81468105 g