Answer: 26.52g
Solution step-by-step:
1) Chemical equation:
2FePO4 + 3Na2SO4 → Fe2(SO4)3 + 2Na3PO4
2) Theoretical molar ratios:
2 mol FePO4 : 3 mol Na2SO4 : 1 mol Fe2(SO4)3 : 2 mol Na3PO4
3) Convert 20.00 g of FePO4 into number of moles
number of moles = mass in grams / molar mass
molar mass of FePO4 = 150.82 g/mol
numer of moles = 20.00 g / 150.82 g/mol = 0.1326 mol FePO4
4) Proportionality
1 mol Fe2(SO4)3 x
----------------------- = ------------------------
2 mol FePO4 0.1326 mol FePO4
Solve for x:
x = (0.1326 / 2) * 1 mol Fe2(SO4)3 = 0.0663 mol Fe2(SO4)3
5) Convert 0.0663 mol Fe2(SO4)3 into grams
mass in grams = number of moles * molar mass
molar mass Fe2(SO4)3 = 399.88 g/mol
mass = 0.0663 mol * 399.88 g/mol = 26.51 g
Depending on the number of decimal digits used by one or other you might obtain 26.52 instead 26.51, that difference does not count.
