percentage yeild

• Even though no atoms are gained or lost in a chemical reaction, it is not always possible to obtain the calculated amount of a product because:

  • the reaction may not go to completion because it is reversible
  • some of the product may be lost when it is separated from the reaction mixture
  • some of the reactants may react in ways different to the expected reaction
• The amount of a product obtained is known as the yeild
• When the yield is compared with the maximum theoretical amount as a percentage, it is called the percentage yield
• % yield is calculated by:

  (mass of the product actually made / maximum theoretical mass of product) x 100