Can someone please help me with this question? If the concentration of flouridat
ID: 684604 • Letter: C
Question
Can someone please help me with this question? If the concentration of flouridated drinking water is 1 X 10-5 M and the calcium ion concentration in blood is 2.5 X 10 -3 M,then why is there no danger of CaF2 precipitating in the bloodstream after drinking the water? Can someone please help me with this question? If the concentration of flouridated drinking water is 1 X 10-5 M and the calcium ion concentration in blood is 2.5 X 10 -3 M,then why is there no danger of CaF2 precipitating in the bloodstream after drinking the water?Explanation / Answer
You can solve this problem by comparing the Ksp forCaF2 (3.9 x 10-11) to the reaction quotientfor the dissolution of CaF2: Q = [Ca2+][F-]2 Q = (2.5 x 10 -3)(1 x 10 -5)2=2.5x 10-12 A smaller Q than Ksp means that the concentration ofproducts are is lower than is at equilibrium. The reaction willtherefore move toward equilibrium by producing more products(dissolving more salt). In other words, a precipitate cannot formbecause the ions are at too low a concentration to precipitate outof solution.