Percentage yield

• What is the term used to describe the amount of product obtained from a chemical reaction?

  Yield
• How can yield be measured?

  In grams or moles
• What do the terms actual yield and theoretical yield refer to?


  Actual yield is the amount obtained, while theoretical yield is the expected amount based on calculations
• If 2 grams of hydrogen reacts with 16 grams of oxygen, what is the theoretical yield of water?


  18 grams
• Why might the actual yield be less than the theoretical yield?


  There are several reasons, including incomplete reactions, side reactions, and product loss
• What is one reason why a reaction might not go to completion?


  The reactants might not fully react
• What is a reversible reaction?


  A reaction where products can revert back to reactants
• In the reaction of nitrogen and hydrogen to make ammonia, why might we not get the expected amount of ammonia?


  Because it is a reversible reaction
• What are side reactions?


  Reactions where reactants produce different products than expected
• If nitrogen reacts with oxygen instead of hydrogen, what product is formed?

  Nitrogen dioxide
• What is one way product loss can occur during a reaction?


  Gaseous products can escape
• What happens when filtering a solution?


  Some liquid or solid may be left behind
• How do you calculate the percentage yield?


  Divide the actual yield by the theoretical yield and multiply by 100
• If the actual yield is 15 grams and the theoretical yield is 18 grams, what is the percentage yield?


  83.3%
• What are the common reasons for not achieving the theoretical yield in a chemical reaction?


  • Reactants might not fully react
  • Side reactions producing different products
  • Loss of product during the process
• How does the concept of theoretical yield relate to practical laboratory work?

  • Theoretical yield is calculated based on stoichiometry
  • Actual yield is what is obtained in practice
  • Percentage yield indicates efficiency of the reaction