3.3 Yield and atom economy of chemical reactions

• Atom economy measures the proportion of atoms from reactants that end up in the desired product.
• What is the formula for calculating atom economy?

  (Molecular weight of desired product / Total molecular weight of reactants) x 100
• What is the definition of yield in chemical reactions?

  Product obtained compared to theoretical maximum
• Steps to calculate theoretical yield

  1️⃣ Write the balanced chemical equation

  2️⃣ Identify the limiting reactant

  3️⃣ Use stoichiometry to determine moles of product

  4️⃣ Convert moles to mass
• What is the formula for calculating percentage yield?

  (Actual Yield / Theoretical Yield) × 100
• Match the concept with its description:

  Atom Economy ↔️ Proportion of reactants converted to desired products

  Yield ↔️ Amount of product obtained compared to theoretical maximum
• A high atom economy minimizes waste and makes the reaction more sustainable.


  True
• Atom economy measures the proportion of atoms from the reactants that end up in the final product
• A high yield indicates an efficient reaction with minimal loss of the desired product.


  True
• A low yield suggests significant losses due to side reactions or incomplete conversion.


  True
• A high atom economy signifies the efficient use of reactants
• What is the theoretical maximum yield of a reaction compared to the actual yield?

  Yield
• A reaction with high atom economy is more sustainable.

  True
• Incomplete reactions occur when the reaction does not go to completion
• Which process can lead to product loss during workup in a reaction?

  Purification
• Minimizing waste in a reaction improves its atom economy
• Reactions with high yield and high atom economy are more environmentally friendly.


  True
• Yield refers to the amount of product obtained from a chemical reaction compared to the theoretical maximum amount that could be produced
• A high yield indicates that a reaction is efficient and produces a large quantity of the desired product


  True
• Match the descriptions with high or low yield:

  High Yield ↔️ Efficient reaction

  Low Yield ↔️ Inefficient reaction
• The theoretical yield is the maximum amount of product that could be produced in a chemical reaction based on the limiting reactant.
• Steps to calculate theoretical yield:

  1️⃣ Write the balanced chemical equation

  2️⃣ Identify the limiting reactant

  3️⃣ Use stoichiometry to determine the maximum product formed
• A low theoretical yield means the limiting reactant was fully consumed during the reaction

  False
• Percentage yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage.
• Steps to calculate percentage yield:

  1️⃣ Determine theoretical yield

  2️⃣ Obtain actual yield

  3️⃣ Apply the formula: Percentage Yield = (Actual Yield / Theoretical Yield) × 100
• A high percentage yield indicates that the reaction was efficient with minimal loss of product


  True
• A low atom economy means a significant portion of the starting materials is lost as waste

  True
• A high atom economy indicates that most of the atoms from reactants end up in the final product.


  True
• A low atom economy indicates that a significant portion of reactants is lost as waste
• A high yield indicates that the reaction produces a large quantity of the desired product.


  True
• Stoichiometry is used to determine the maximum moles of product that can be formed from the limiting
• A high percentage yield indicates that the reaction is efficient and minimal product is lost.


  True
• The formula for atom economy includes the molecular weight of the desired product
• In the reaction CH₄ + 2 O₂ → CO₂ + 2 H₂O, what is the atom economy if CO₂ is the desired product?

  55%
• Yield and atom economy are both important measures of the efficiency of a chemical reaction, but they focus on different aspects
• Atom economy measures the proportion of atoms from the reactants that end up in the final product
• What does a high atom economy indicate about the use of starting materials?

  Minimal waste
• Low atom economy results in significant waste production.

  True
• A low atom economy means a large portion of the reactants are lost as by-products
• What is one factor that reduces the yield of a chemical reaction?

  Side reactions