Theoretical Yield of H3PO4? - Show Work Please

Question

Question: 93.8 grams of PCl5 react with 20.3 grams of H2O. How many grams of H3PO4 would be produced (theoretical yield)?

 

Equation: PCl5 + 4H2O = H3PO4 + 5HCl

Answer 1

PCl5 + 4H2O = H3PO4 + 5HCl

moles PCl5 = 93.8 g x 1 mol/208 g = 0.451 moles

moles H2O = 20.3 g x 1 mol/18 g = 1.13 moles 

Limiting reactant is H2O 

 

Theoretical yield H3PO4 = 1.13 moles H2O x 1 mole H3PO4/4 moles H2O = 0.283 moles H3PO4

0.283 moles H3PO4 x 98 g/mole = 27.7 g H3PO4