Question

Feedback See Periodic Table O See Hint What is the pH of a solution made by dissolving 6.86 grams of calcium fluoride in enough water to make 590 mL of solution? The K, for HF is 6.8x10-4 ® 2.8

Answer 1

Ftions in solution are conjugate base and will give you a baric solution, Cafe = 6.869 x romole la 0:0879 molee Oo [F = 2 x 0.0879 0.2979 m. 0.591 we need the kb . :: Ko = hea = box -4 = .. kha kw 1810-14 - 1.47x 10-11 The equation we need to look is :- F + H2O = HF +OH after making ICE terble, we get 0 K6 = x² 0979 =) dermeny «< 0.2979 m solucing for x 2 = 2.092x10-6M = [OH-] f you add 1x 10-7 from water, you get pon = -log (2.092x10-6M) pole -0.3206 +6 = 5-679 pH = 14- pou - 14-5-679 = 8:32