Answer:
Step-by-step explanation:
The formula for calcium carbonate is CaCO3, which consists of one calcium atom, one carbon atom, and three oxygen atoms.
We can use the density and molar mass of calcium carbonate to find the number of moles of the compound in a 10.00 cm³ sample:
mass = density x volume
mass = 2.710 g/cm³ x 10.00 cm³
mass = 27.10 g
The molar mass of CaCO3 is the sum of the atomic masses of its elements, which are:
Calcium (Ca): 40.08 g/mol
Carbon (C): 12.01 g/mol
Oxygen (O): 16.00 g/mol (x 3 atoms)
Molar mass of CaCO3 = 40.08 g/mol + 12.01 g/mol + (16.00 g/mol x 3) = 100.09 g/mol
Number of moles of CaCO3 = mass / molar mass = 27.10 g / 100.09 g/mol = 0.2703 mol
Since there are three oxygen atoms in one molecule of CaCO3, the number of oxygen atoms in the sample is:
Number of oxygen atoms = 0.2703 mol x 3 = 0.8109 mol of O atoms
To convert this to the number of oxygen atoms, we use Avogadro's constant, which is 6.022 × 10^23 particles per mole:
Number of oxygen atoms = 0.8109 mol x 6.022 × 10^23 atoms/mol ≈ 4.882 × 10^23 oxygen atoms
Therefore, there are approximately 4.882 × 10^23 oxygen atoms in a 10.00 cm³ sample of calcium carbonate.