Final answer:
The percent composition of oxygen in Ca3(PO4)2 is calculated by dividing the mass of oxygen in the compound by the formula mass of the entire compound and multiplying the result by 100%, resulting in 41.265%.
Step-by-step explanation:
The percent composition of oxygen in calcium phosphate, or Ca3(PO4)2, can be found by determining the total mass of oxygen in the compound and dividing it by the formula mass of the entire compound. The mass of oxygen in Ca3(PO4)2 is given by the sum of the masses of 8 oxygen atoms:
- 8 O: (8 atoms) (15.9994 amu/atom) = 127.9952 amu
The formula mass of Ca3(PO4)2 is calculated by adding the atomic masses of all atoms in the compound:
- 3Ca: (3 atoms) (40.078 amu/atom) = 120.234 amu
- 2P: (2 atoms) (30.973761 amu/atom) = 61.947522 amu
- 8O: (8 atoms) (15.9994 amu/atom) = 127.9952 amu
The total formula mass of Ca3(PO4)2 is therefore:
- Formula mass of Ca3(PO4)2 = 310.177 amu
To find the percent composition of oxygen, divide the mass of oxygen by the total formula mass and then multiply by 100:
- Percent composition of O = (127.9952 / 310.177) × 100%
Calculating this gives us the percent composition of oxygen in Ca3(PO4)2 to three decimal places:
- Percent composition of O = 41.265%