If 10g of phosphine is made to react with 15g of chlorine gas, calculate the percentage yield if 5.5g of phosphorus pentachloride was experimentally produced
This is a limiting reagent (LR) problem. Using the procedure outlined by Bob P below, find how much PCl5 should be produced. Tha't the theoretical yield (TY). The actual yield (AY) is 5.5 g.
%yield = (AY/TY)*100 = ?
To calculate the percentage yield, you need to compare the experimental yield (actual amount produced) with the theoretical yield (amount that should have been produced according to stoichiometry).
First, you need to determine the balanced chemical equation for the reaction between phosphine (PH₃) and chlorine gas (Cl₂):
2 PH₃ + 5 Cl₂ → PCl₅ + 5 HCl
From the balanced equation, you can see that 2 moles of PH₃ react with 5 moles of Cl₂ to produce 1 mole of PCl₅.
Next, calculate the theoretical yield of PCl₅.
Step 1: Convert the given mass of phosphine (PH₃) to moles:
10g PH₃ * (1 mole PH₃ / molar mass of PH₃) = x moles PH₃
Step 2: Calculate moles of Cl₂ required based on the stoichiometry:
Since the molar ratio between PH₃ and Cl₂ is 2:5,
x moles PH₃ * (5 moles Cl₂ / 2 moles PH₃) = y moles Cl₂
Step 3: Use the mole ratio between PH₃ and PCl₅ to determine the theoretical yield:
Since the molar ratio between PH₃ and PCl₅ is 2:1,
y moles Cl₂ * (1 mole PCl₅ / 5 moles Cl₂) = z moles PCl₅
Step 4: Convert moles of PCl₅ to grams:
z moles PCl₅ * (molar mass of PCl₅ / 1 mole PCl₅) = theoretical yield of PCl₅
Now that you have the theoretical yield of PCl₅, you can calculate the percentage yield:
Percentage yield = (experimental yield / theoretical yield) * 100%
Given that the experimental yield is 5.5g of PCl₅, you can substitute the values into the formula:
Percentage yield = (5.5g / theoretical yield) * 100%
By following these steps and performing the calculations, you can determine the percentage yield for the reaction.