To determine the number of oxygen atoms present in a given mass of barium phosphate (Ba3(PO4)2), we need to follow these steps:
Step 1: Calculate the molar mass of barium phosphate. Ba3(PO4)2 contains 3 barium atoms, 2 phosphate groups (each containing 1 phosphorus atom and 4 oxygen atoms), and a total of 2 × 4 = 8 oxygen atoms. The molar mass of barium phosphate can be calculated as follows: Molar mass of Ba3(PO4)2 = (3 × atomic mass of Ba) + (2 × atomic mass of P) + (8 × atomic mass of O) = (3 × 137.5) + (2 × 31) + (8 × 16) = 412.5 + 62 + 128 = 602.5 g/mol
Step 2: Calculate the number of moles of barium phosphate. Given mass of barium phosphate = 6.02 g Number of moles = given mass / molar mass = 6.02 g / 602.5 g/mol ≈ 0.01 mol
Step 3: Calculate the number of moles of oxygen atoms. Since there are 8 oxygen atoms in each mole of barium phosphate, the number of moles of oxygen atoms can be calculated as follows: Number of moles of oxygen atoms = number of moles of barium phosphate × 8 ≈ 0.01 mol × 8 = 0.08 mol
Step 4: Calculate the number of oxygen atoms. Avogadro's number states that there are 6.022 × 10^23 atoms in one mole of any substance. Number of oxygen atoms = number of moles of oxygen atoms × Avogadro's number = 0.08 mol × (6.022 × 10^23 atoms/mol) ≈ 4.8176 × 10^22 oxygen atoms
Therefore, there are approximately 4.8176 × 10^22 oxygen atoms present in 6.02 g of barium phosphate.