Exercise 4
Write the dissolution reaction for fluorapatite and the mass action expression for the ion-activity product. If the activities of free Ca2+ = 3.895 × 10–5, free PO43– = 3.065 × 10–10, and free F– = 2.009 × 10–4, calculate the saturation index and state whether the solution is undersaturated or oversaturated with respect to fluorapatite. Use log Kfluorapatite = –55.1