How many grams of phosphorus are contained in 31 grams of calcium phosphate?
- 3.1 g
- 6.2 g
- 12.4 g
- 1.55 g
📝 Detailed explanation
Formula of calcium phosphate is Ca₃(PO₄)₂.Molar mass = (3 × 40) + 2 × (31 + 64) = 120 + 2 × 95 = 120 + 190 = 310 g/mol.
One mole (310g) contains 2 moles of P (62g).
31 g of the salt contains 62 × (31 / 310) = 6.2 g.