1) M (Ca3(PO4)2) = 40 × 3 + (31 + 16 × 4) × 2 = 310 г/моль
2) M (Al2(SO4)3 = 27 × 2 + (32 + 16 × 4) × 3 = 342 г/моль
W (O) = (12 × 16) / 342 = 0,5614 × 100 = 56,14%
1) M (Ca3(PO4)2) = 40 × 3 + (31 + 16 × 4) × 2 = 310 г/моль
2) M (Al2(SO4)3 = 27 × 2 + (32 + 16 × 4) × 3 = 342 г/моль
W (O) = (12 × 16) / 342 = 0,5614 × 100 = 56,14%