emperical formula and percentage yeild

• Empirical formula


  Shows the simplest ratio of the atoms present
• Molecular formula


  Shows the numbers of each atom in the molecule
• Finding molecular formula


  1. Use empirical formula

  2. Use relative molecular mass of empirical formula

  3. Use relative molecular mass of molecule
• Yield


  The amount of product formed in a chemical reaction
• Theoretical yield


  The maximum possible amount of product from the reactants used
• Actual yield is usually much less than the theoretical yield due to factors like impure reactants, reaction not going to completion, and difficulty purifying the product</b>
• Percentage yield

  How close the actual yield is to the theoretical yield
• In the Haber process, the percentage yield of ammonia is only about 15% due to the reversible and incomplete nature of the reaction
• Calculating mass of ammonia produced in Haber process

  1. Convert mass of hydrogen to moles

  2. Use mole ratio from reaction equation to calculate moles of ammonia

  3. Convert moles of ammonia to mass
• The actual mass of ammonia produced with 15% yield is 5.1 tonnes