A hard water solution contains 4.8 g of calcium chloride. How much sodium phosphate in grams should be added to the solution to completely precipitate all of the calcium?
Here, we have to determine the amount of sodium phosphate required to precipitate all of the calcium.
3CaCl2(aq) +2 Na3(PO4)------> 6NaCl(s) + Ca3(PO4)2
Molar mass of CaCl2 =110.98 g/mol
Molar mass of Na3(PO4) =163.94 g/mol
g CaCl2(aq)= mol CaCl2(aq) = g Na3(PO4) = mol Na3(PO4)
Thus the amount of sodium phosphate required
= 4.8 g CaCl2(aq) x x x...