How many grams are in 2.3 x10-4 moles of calcium phosphate ca3 (po3) 2

calcium phosphate has the formula Ca3 (PO4) 2, which has the mass of 310 grams/mol.

1 mol contains 310 grams

2.3*10^-4 moles contain 2.3*10^-4 * 310, which means 713*10^-4 grams, or 71.3 milligrams.

If you wrote the formula right and named the compound wrong, all you have to do is replace 310 with 278 and the answer will be 639.4*10^-4 grams, or 63.94 milligrams.