5.5.1 Calculating Percentage Yield

• Percentage yield is the ratio of the actual yield of a product obtained to its theoretical yield, expressed as a percentage.
• What is the formula for percentage yield?

  $\frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100$
• The actual yield is the amount of product actually obtained in a reaction.
• The theoretical yield is the maximum amount of product that can be obtained based on stoichiometry.
• What is the first step to find the actual yield?

  Read the experiment
• If you collected 25 grams of product, the actual yield is 25 grams.
• The theoretical yield is the maximum amount of product that can be obtained from a reaction based on stoichiometry.
• What is the first step in calculating the theoretical yield?

  Identify limiting reactant
• To calculate moles of the limiting reactant, use the formula \text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}.
• In the reaction $2A +$$B \rightarrow C$, what is the number of moles of A if 10 g of A (molar mass 50 g/mol) is used?


  0.2 moles
• In the reaction $2A +$$B \rightarrow C$, the number of moles of C produced from 0.2 moles of A is 0.1 moles.
• What is the theoretical yield of C in the reaction $2A +$$B \rightarrow C$ if 0.2 moles of A are used and the molar mass of C is 100 g/mol?


  10 g
• To apply the percentage yield formula, you first need to obtain the actual yield from the experiment.
• If the actual yield of C is 8 g and the theoretical yield is 10 g, what is the percentage yield?

  80%
• Percentage yield is calculated by dividing the actual yield by the theoretical yield and multiplying by 100.
• The theoretical yield is determined using stoichiometry
• In the reaction \( 2A + B \rightarrow C \), if 10 g of A yields 8 g of C and the theoretical yield is 10 g, the percentage yield is 80%.
• What is the formula for calculating percentage yield?

  $\frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100$
• Match the yield type with its definition and formula:

  Actual Yield ↔️ The amount of product obtained in an experiment ||| Measured from experiment

  Theoretical Yield ↔️ The maximum product amount predicted by stoichiometry ||| Calculated using balanced equation
• If the actual yield is 25 g and the theoretical yield is 30 g, the percentage yield is 83.3%.
• What does percentage yield indicate about a chemical reaction?

  Its efficiency
• Percentage yield is calculated by dividing the actual yield by the theoretical yield and multiplying by 100
• The actual yield is the amount of product obtained from an experiment.
• Steps to identify the actual yield

  1️⃣ Read the experiment and note the amount of product collected

  2️⃣ Ensure the units are consistent with the theoretical yield

  3️⃣ Use the given data to determine the actual yield
• What is the theoretical yield based on?

  Stoichiometry
• To calculate the theoretical yield, the first step is to identify the limiting reactant
• The limiting reactant is the reactant that limits the amount of product formed in a reaction.
• What formula is used to calculate the moles of a limiting reactant?

  $\text{Moles} =$$\frac{\text{Mass}}{\text{Molar Mass}}$
• When calculating the moles of product, the stoichiometric ratio from the balanced equation is used.
• What formula is used to calculate the mass of a product?

  \text{Mass} = \text{Moles} \times \text{Molar Mass}</latex>
• In the reaction \( 2A + B \rightarrow C \), if10 g of A (molar mass 50 g/mol) reacts, the moles of A are 0.2
• Match the step in theoretical yield calculation with its result:

  Moles of A ↔️ 0.2 moles

  Stoichiometric ratio A:C ↔️ 2:1
• The first step in calculating theoretical yield is to identify the limiting reactant.
• The formula to calculate moles is \( \text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}} \)
• What is the purpose of using stoichiometry in calculating theoretical yield?

  Find the ratio
• To calculate the mass of the product, you multiply the moles by the molar mass.
• The theoretical yield represents the maximum amount of product possible based on stoichiometry.
• Steps to calculate the theoretical yield.

  1️⃣ Identify the limiting reactant

  2️⃣ Calculate the moles of the limiting reactant

  3️⃣ Use stoichiometry to find reactant-product ratio

  4️⃣ Calculate the moles of product

  5️⃣ Calculate the mass of product
• What is the theoretical yield based on in a balanced chemical equation?

  Stoichiometry
• Match the steps in calculating percentage yield with their description:

  Obtain actual yield ↔️ Experimental result

  Calculate theoretical yield ↔️ Using stoichiometry

  Divide actual by theoretical yield ↔️ Find the ratio

  Multiply by 100 ↔️ Express as a percentage