Final answer:
The empirical formula of calcium phosphate indicates that the simplest unit contains three calcium ions and two phosphate ions. The formula mass of Ca3(PO4)2 is calculated by adding together the atomic masses of the individual atoms in the compound.
Step-by-step explanation:
The empirical formula for calcium phosphate is Ca3(PO4)2, which indicates that the simplest electrically neutral unit of calcium phosphate contains three Ca2+ ions and two PO43- ions. To determine the number of oxygen atoms, we need to calculate the formula mass of Ca3(PO4)2. The formula mass is calculated by adding together the atomic masses of the individual atoms in the compound. The molar mass of Ca is 40.078 g/mol, the molar mass of P is 30.974 g/mol, and the molar mass of O is 15.999 g/mol.
The formula mass of Ca3(PO4)2 is calculated as follows: Calculate the mass of three Ca atoms: 3 * 40.078 g/mol = 120.234 g/mol. Therefore, the formula mass of Ca3(PO4)2 is 310.174 g/mol. To find the number of oxygen atoms in 5.00 g of calcium phosphate, we can use the molar mass and the concept of moles. First, calculate the number of moles of calcium phosphate: 5.00 g / 310.174 g/mol = 0.016 moles. Since the empirical formula indicates that two PO43- ions are present in each formula unit, a total of 2 * 8 = 16 oxygen atoms are present in each formula unit. Therefore, the number of oxygen atoms in 0.016 moles of calcium phosphate is: 0.016 moles * 16 oxygen atoms/mole = 0.256 oxygen atoms.