... complex mineral apatite. This mineral contains, in addition to phosphate, silica and the following ions: Ca2+, 2-3CO, 2-4SO, 2-3SiO, and F–. Let us assume that this mineral is a mixture ... is soluble in water, has been prepared. For this purpose, apatite is treated with a mixture of phosphoric and sulphuric acid. At the same time this operation eliminates the majority of impurities. ... Operation 2 - 1.00 g of this residue is treated with 50.0 cm3 of water at 40 °C, then filtered, dried and weighed. The mass of the residue obtained is m2. This new residue is mainly...