What is the percent yield of a reaction in which 200. g of phosphorus trichloride reacts with excess water to form 91.0 g of hcl and aqueous phosphorous acid (h3po3)?

The percentage yield of HCl obtained from the reaction is 57.1%

We'll begin by calculating the mass of PCl₃ that reacted and the mass of HCl produced from the reaction.

PCl₃ + 3H₂O → 3HCl + H₃PO₃

Molar mass of PCl₃ = 31 + (3×35.5) = 137.5 g/mol

Mass of PCl₃ from the balanced equation = 1 × 137.5 = 137.5 g

Molar mass of HCl = 1 + 35.5 = 36.5 g/mol

Mass of HCl from the balanced equation = 3 × 36.5 = 109.5 g

SUMMARY:

From the balanced equation above,

137.5 g of PCl₃ reacted to produce 109.5 g of HCl

From the balanced equation above,

137.5 g of PCl₃ reacted to produce 109.5 g of HCl.

Therefore,

200 g of PCl₃ will react to produce = k200 × 109.5) / 137.5 = 159.3 g of HCl.

Actual yield of HCl = 91 g

Theoretical yield of HCl = 159.3 g

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