## Chemistry and Chemical Reactivity (9th Edition)

$75.1\ kg\ Ca_3(PO_4)_2$
Calcium phosphate's molecular formula: $Ca_3(PO_4)_2$ Atomic weights (g/mol): $Ca: 40.078,\ P: 30.974,\ O: 15.999$ Molar mass: $310.17\ g/mol$ Mass fraction of P: $2\times30.974/310.17\times100\%=19.97\%$ For 15.0 kg of P: $15.0\ kg\ P\div(19.97 \ kg\ P/100\ kg\ Ca_3(PO_4)_2)=75.1\ kg\ Ca_3(PO_4)_2$