Consider the balanced equation. PCl3 + 3H2O Right arrow. H3PO3 + 3HCl What is the percent yield of HCl if 42.0 g of HCl are produced from the reaction of 62.0 g of PCl3? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100..

Percient yield of reaction: 85 %

Explanation:

The reaction is:

PCl₃ + 3H₂O → H₃PO₃ + 3HCl

We only have data from the chloride, so we assume water is in excess. We convert the mass to moles:

62 g . 1mol / 137.32 g = 0.452 mol

If ratio is 1:3, from 0.452 mol we would produce three times as big, that amount. (0.452 . 3) = 1.36 moles of HCl.

We convert the amount to mass.

1.36 mol . 36.45g / 1mol = 49.4 g

This value of produced HCl is the theoretical yield. To determine the percent yield we make:

(Yield produced / Theoretical yield) . 100

(42 g / 49.4g) . 100 = 85%