Percentage Yield

• What does percentage yield compare?

  Actual yield and theoretical yield
• How is percentage yield calculated?

  mass of product actually made / maximum theoretical mass of product x 100
• What is the maximum percentage yield possible?

  Always less than 100%
• Why are yields always less than 100%?

  • Not all reactants react to make a product
  • Side reactions may occur
  • Product loss during separation
• What happens in reversible reactions regarding yield?

  Products can revert to reactants, lowering yield
• In the Haber process, what reactions occur simultaneously?

  N₂ + 3H₂ ⇆ 2NH₃ and 2NH₃ ⇆ N₂ + 3H₂
• What might cause side reactions in a chemical process?

  Reactants reacting with gases or impurities
• What happens when you filter a liquid to remove solid particles?

  You lose some liquid or solid during the process
• What is a common issue when transferring materials between containers?

  Some material is left behind in the old container
• Is a yield of 100% in a reaction possible?

  No, it is pretty much impossible
• What is necessary to achieve 100% in an exam?

  Luck and thorough preparation
• If a student has a maximum theoretical yield of 2.72 g and an actual yield of 2.31 g, what is the percentage yield?

  $85.04\%$
• How do you calculate the percentage yield of a reaction?

  1. Identify actual yield and theoretical yield
  2. Use the formula:

  • percentage yield = (actual yield / theoretical yield) x 100

  1. Substitute values and calculate