✔ 最佳答案
Calculate moles of Na^ ion:
moles Na^ = V in liters x molarity = (0.700 L)(0.800 mol/L) = 0.560 mole Na^ ion
Now calculate the moles of Na3PO4 needed to provide this concentration of Na^ ion.
moles Na3PO4 = 0.560 mole Na^ (1 mol Na3PO4)/(3 mol Na^ ) = 0.187 mol Na3PO4
formula mass Na3PO4 = 163.94 g/mol
mass Na3PO4 needed = moles Na3PO4 x formula mass = (0.187 mol)(163.94 g/mol)
mass Na3PO4 = 30.60 g
Hope this is helpful to you. JIL HIR