Pure water is saturated with slightly soluble calcium fluoride,CaF₂.Which of the following is true concerning the equilibrium concentration of Ca²⁺? B)[Ca²⁺] = [F^-] E)[Ca²⁺] = K_sp

Question

Quizplus · Accepted Answer

Since calcium fluoride is slightly soluble, the concentration of Ca2+ and F- ions in solution would be very small. Therefore, the concentration of CaS+ and P2- ions, which are the product of the reaction between Ca2+ and F-, would also be very small. This means that option A is incorrect since the concentration of CaS+ and P2- ions would be negligible compared to the concentration of Ca2+ and F- ions. Option B is incorrect since the concentration of CaS+ and P2- ions would not be equal to the concentration of FS- ions since they are not present in the same amount. Option E is incorrect since the equilibrium constant for the dissolution of calcium fluoride, Ksp, is a constant value and does not change based on the concentration of CaS+ and P2- ions. Therefore, the correct answer is option D, which states that the equilibrium concentration of CaS+ and P2- ions would be very small.

Pure Water Is Saturated with Slightly Soluble Calcium Fluoride,CaF2

Pure Water Is Saturated with Slightly Soluble Calcium Fluoride,CaF₂