Convert 25.4 grams of barium phosphate, Ba3(PO4)2 to formula units.

To solve this questions you first need to find the number of moles of barium phosphate you have. The molar mass of barium phosphate is 601.93g/mol.
24.4/601.83 = 0.0402 moles barium phosphate
Then you need to use avagadro’s number, 6.022 x 10^23, which is the number of molecules or formula units in a mole.

6.022 x 10^23 * 0.0402 = 2.42 x 10^22 formula units