J.R. S. answered 12/04/20
Ph.D. University Professor with 10+ years Tutoring Experience
3Ba(NO3)2 + Al2(SO4)3 ==> 3BaSO4(s) + 2Al(NO3)3 ... balanced equation
To find the mass of BaSO4 formed, we first must find which reactant is limiting:
moles Ba(NO3)2 = 500.0 ml x 1 L/1000 ml x 316.2 mg/L x 1 g/1000 mg x 1 mol/261 g = 6.057x10-4 moles
moles Al2(SO4)3 = 150.0 ml x 1 L/1000 ml x 0.047 mol/L = 7.05x10-3 moles
So, Ba(NO3)2 is limiting and determines moles of BaSO4 that will be produced
mass BaSO4 produced = 6.057x10-4 mol Ba(NO3)2 x 3 mol BaSO4 / 3 mol Ba(NO3)2 x 233 g/mol = 0.1441 g
Molar concentration of unreacted reagent would refer to Al2(SO4)3:
moles left = 7.05x10-3 mol - 0.6057x10-3 mol = 6.44x10-3 moles / 0.650 L = 9.91 M