3.3 Yield and atom economy of chemical reactions

• The use of a catalyst can increase the yield of a reaction.


  True
• The percentage yield is calculated using the formula: Percentage yield = (Actual yield / Theoretical yield) × 100
• Atom economy focuses on the percentage of reactant mass in the product
• The ideal value for atom economy is 100%.

  True
• What effect does an incomplete reaction have on yield?

  Decreases yield
• Why is the actual yield often less than the theoretical yield?

  Incomplete reactions or losses
• Atom economy and yield both measure the same aspect of a chemical reaction.

  False
• What is the focus of atom economy in chemical reactions?

  Efficiency of converting raw materials
• Stoichiometry is a factor that affects atom economy.


  True
• What does yield measure in a chemical reaction?

  Amount of product obtained
• What is the goal in chemistry regarding yield and atom economy?

  Maximize both
• Theoretical yield is based on the stoichiometry of the balanced equation.
• Match the yield type with its characteristic:

  Theoretical Yield ↔️ Maximum calculated product

  Actual Yield ↔️ Measured amount of product obtained
• Atom economy measures how efficiently raw materials are converted into the target compound.


  True
• What is the formula for calculating atom economy?

  $\frac{\text{Mass of desired product}}{\text{Total mass of reactants}} \times 100$
• What is the goal in chemistry regarding yield and atom economy?

  Maximize both
• How do incomplete reactions affect yield?

  Decrease yield
• Match the factor with its effect on atom economy:

  Stoichiometry ↔️ Ensures maximum product mass

  Side Reactions ↔️ Reduces atom economy

  Catalyst Use ↔️ Increases atom economy

  Starting Materials ↔️ Optimizes product conversion
• Match the characteristic with the correct concept:

  Definition ↔️ Percentage of reactant mass in product ||| Actual product amount vs. theoretical maximum

  Focus ↔️ Efficiency of converting raw materials ||| Quantity of product obtained
• Incomplete reactions and side reactions can decrease the actual yield of a reaction.
• Catalysts can increase the yield of a reaction.


  True
• What is the definition of actual yield in a chemical reaction?

  Measured amount of product obtained
• What is the formula for calculating percentage yield?

  $\frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100$
• What is the formula for calculating atom economy?

  $\frac{\text{Mass of desired product}}{\text{Total mass of reactants}} \times 100$
• What does atom economy measure?

  Efficiency of raw materials
• Match the characteristic with the correct term:

  Product amount vs. theoretical maximum ↔️ Yield

  Percentage of reactant mass in product ↔️ Atom Economy
• The ideal value for both yield and atom economy is 100%.

  True
• Losses during workup and purification can decrease the final isolated yield.
• What does maximizing atom economy lead to?

  Less waste
• What is the theoretical yield of hydrogen gas when 10g of water is electrolyzed according to the equation 2H_{2}O(l) \rightarrow 2H_{2}(g) + O_{2}(g)</latex>?

  1.11 grams
• To solve GCSE chemistry problems, the first step is to understand the question.
• Yield in a chemical reaction refers to the amount of product obtained compared to the theoretical maximum
• The theoretical yield is the maximum amount of product calculated based on the limiting
• What is atom economy a measure of in a chemical reaction?

  Efficiency
• What is the definition of atom economy in chemical reactions?

  Percentage of reactant mass in product
• Atom economy is a measure of the efficiency of a reaction.
• Atom economy measures the percentage of the total mass of reactants that ends up in the desired product.


  True
• Order the factors affecting yield from most negative to most positive effect:

  1️⃣ Incomplete reaction

  2️⃣ Side reactions

  3️⃣ Losses during purification

  4️⃣ Optimized reaction conditions

  5️⃣ Catalyst use
• Side reactions can lower the actual yield of a reaction.


  True
• If the theoretical yield is 25g and the actual yield is 20g, the percentage yield is 80%.