Final answer:
The formula weight of calcium phosphate, Ca3(PO4)2, is 310.177 amu, which is found by summing the atomic weights of three calcium atoms, two phosphorus atoms, and eight oxygen atoms, leading to the correct answer of D. 310 amu.
Step-by-step explanation:
To determine the formula weight of calcium phosphate, Ca3(PO4)2, the weight of all atoms present in the formula must be summed up. This ionic compound includes three calcium ions, two phosphorus ions, and eight oxygen ions. The calculation is as follows:
- For Calcium (Ca): 3 atoms x 40.078 amu/atom = 120.234 amu
- For Phosphorus (P): 2 atoms x 30.973761 amu/atom = 61.947522 amu
- For Oxygen (O): 8 atoms x 15.9994 amu/atom = 127.9952 amu
By adding these amounts together, the formula mass of Ca3(PO4)2 is calculated to be:
120.234 amu + 61.947522 amu + 127.9952 amu = 310.177 amu
Therefore, the correct answer is D. 310 amu.