J.R. S. answered 02/12/19
Ph.D. University Professor with 10+ years Tutoring Experience
2H3PO4 + 3BaCl2 -> Ba3(PO4)2 + 6HCl ... balanced equation
moles H3PO4 present = 1.3 g x 1 mole/97.99 g = 0.013 moles H3PO4
moles BaCl2 present = 4.5 g x 1 mole/208 g = 0.0216 moles BaCl2
Find limiting reactant:
H3PO4: 0.013 moles x 1 mol Ba3(PO4)2/2 mol H3PO4 = 0.0065 moles Ba3(PO4)2 produced
BaCl2: 0.0216 moles x 1 mol Ba3(PO4)2/3 mol BaCl2 = 0.0072 moles Ba3(PO4)2 produced
H3PO4 is LIMITING
From above calculations, the theoretical yield Ba3(PO4)2 = 0.0065 moles
Theoretical mass produced = 0.0065 moles x 602 g/mole = 3.9 g
% yield = actual/theoretical (x100) = 1.2/3.9 (x100) = 30.8% = 31% yield (to 2 significant figures)
William W.
I probably should have said to take the number of GRAMS of Ba3(PO4)2 actually created divided by the number of theoretical grams of Ba3(PO4)2 that should have been created (instead of telling you to use moles) but the answer is exactly the same. Percent yield is usually defined as grams created divided by theoretical grams that should have been created).02/12/19