To calculate the percent composition of calcium (Ca) in calcium oxide (CaO), we first need to determine the molar masses of calcium and oxygen.
The molar mass of calcium (Ca) is approximately 40.08 g/mol, and the molar mass of oxygen (O) is about 16.00 g/mol. Therefore, the molar mass of calcium oxide (CaO) can be calculated as follows:
Molar mass of CaO = Molar mass of Ca + Molar mass of O
Molar mass of CaO = 40.08 g/mol + 16.00 g/mol = 56.08 g/mol
Now that we have the molar mass of CaO, we can find the percent composition of calcium in CaO using the following formula:
Percent Composition of Ca = (Molar mass of Ca / Molar mass of CaO) × 100
Substituting the values we have:
Percent Composition of Ca = (40.08 g/mol / 56.08 g/mol) × 100
Percent Composition of Ca ≈ 71.42%
Therefore, the percent composition of calcium in calcium oxide is approximately 71.42%. This means that in any given sample of CaO, about 71.42% of its mass comes from calcium.