Percentage Yield: Calculation of the percentage of yield obtained from the theoretical yield. In practice, some product will be lost during the process when purifying the product by filtration or evaporation or when transferring a liquid or when heating.
Percentage Yield = ( Yield Obtained / Theoretical Yield ) x 100
In an experiment to displace copper from copper sulfate, 6.5 g of Zinc was added to an excess of copper (II) sulfate solution. The copper was filtered off, washed and dried. The mass of copper obtained was 4.8 g. Calculate the percentage yield of copper.
Equation Of Reaction: Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)
Step 1: Calculate the Amount, in Moles of Zinc Reacted
Moles of Zinc = 6.5 ÷ 65 = 0.10 moles
Step 2: Calculate the Maximum Amount of Copper that could be Formed
Maximum Moles of Copper = 0.10 moles
Step 3: Calculate the Maximum Mass of Copper that could be Formed
Maximum Mass of Copper = ( 0.10 x 64 ) = 6.4 g
Step 4: Calculate the Percentage of Yield of Copper
Percentage Yield = ( 4.8 ÷ 6.4 ) x 100 = 75%
Percentage Yield of Copper = 75%