In addition to having a low solubility, the precipitate must be free from impurities. For example, the K sp of PbSO 4 is 2 × 10 –8 in H 2O and 2.6 × 10 –12 in a 50:50 mixture of H 2O and ethanol. The poorer solvating ability of non-aqueous solvents, even those which are polar, leads to a smaller solubility product. A precipitate’s solubility is generally greater in an aqueous solution because of water’s ability to stabilize ions through solvation. When solubility is a concern, it may be possible to decrease solubility by using a non-aqueous solvent. Because the solubility of CaF 2 spans several orders of magnitude, its solubility is shown in logarithmic form. Note that the solubility of CaF 2 is independent of pH for pH levels greater than 4.17, and that its solubility increases dramatically at lower pH levels where HF is the predominate species. The predominate form of fluoride in solution is shown by the ladder diagram along the x-axis, with the black rectangle showing the region where both HF and F – are important species. The solid blue curve is a plot of equation 8.11. At more acidic pH levels, the solubility of CaF 2 increases because of the contribution of reaction 8.9.įigure 8.2 Solubility of CaF 2 as a function of pH. When the pH is greater than 4.17, the predominate species is F – and the solubility of CaF 2 is independent of pH because only reaction 8.8 occurs to an appreciable extent. Depending on the solution’s pH, the predominate form of fluoride is either HF or F –. Problem 4 in the end-of-chapter problems asks you to show that equation 8.11 is correct by completing the derivation.įigure 8.2 shows how pH affects the solubility of CaF 2. Announces Results and Interpretation of the Airborne Geophysical Survey Conducted over the Entire Motherlode Gold Project, Within the Burin Peninsula of Southern Newfoundland, Canada announced that it expects to receive CAD 0.75 million in funding Precipitate Gold Upsizes Private Placement of Flow-Through, Non-Flow Through Units announced that it has received CAD 2.17939 million in funding Reports Earnings Results for the Full Year Ended November 30, 2021 Reports Earnings Results for the First Quarter Ended February 28, 2022 Receives USD 5.0 Million Cash and 3% NSR from Barrick Gold Corporation for Relinquishing Non-Core Areas of Pueblo Grande Project in Amendment to Ongoing Exploration Earn-In Agreement Commences Field Work At Motherlode Gold Project in Newfoundland, Canada Commences Ground Geophysical IP Survey At Motherlode Gold Project in Newfoundland, Canada Reports Earnings Results for the Second Quarter and Six Months Ended May 31, 2022 Precipitate's IP Geophysical Survey Identifies Drill Targets at Motherlode Gold Project in Newfoundland, Canada Appoints Stephen Sulis as Chief Financial Officer Receives Drill Permit for Motherlode Gold Project in Newfoundland, Canada Precipitate Gold Obtains Drill Permit for Motherlode Gold Project in Newfoundland, Canada Commences Drilling at Motherlode Gold Project in Newfoundland, Canada Precipitate Gold Begins Drilling at Motherlode Gold Project in Newfoundland, Canada Reports Earnings Results for the Third Quarter and Nine Months Ended August 31, 2022 Precipitate Completes 2,700 Metre Drill Program At Motherlode Gold Project in Newfoundland, Canada Reports Motherlode Gold Project Drilling and Intersects Targeted Pyrite-Gold Zone Reports Earnings Results for the Full Year Ended November 30, 2022 Reports Earnings Results for the First Quarter Ended February 28, 2023 Reports Earnings Results for the Second Quarter and Six Months Ended May 31, 2023
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |