theoretical yield 

• The theoretical yield for any given reaction can be worked out using the balanced equation for that reaction
• NaOH + HCI → NaCI + H₂O
• If we know the mass of the limiting reagent used we can work out the theoretical yield

Method

• NaOH + HCI→ NaCI + H₂O
• Given a mass of 10g of NaOH what is the theoretical yield of NaCI?
• Work out number of moles of NaOH (mass/Mr)
• 10/40 = 0.25 0.25 moles
• Look at the ratio of moles of NaOH to NaCI
• This is 1:1
• Work of mass of NaCI
• 0.25 x 58.5 = 14.625

Percentage yield

• In all cases no reactions actually produce the theoretical yield

• The reaction will never go to completion

• The actual yield will be lower

• Percentage yield = actual yield / theoretical yield x100