Percentage yield

• In a lot of reactions, not all reactants react to form products which can be due to several factors:
  • Other reactions take place simultaneously
  • The reaction does not go to?completion
  • Products are?lost?during separation and purification
• The?percentage yield?shows how much of a particular product you get from the reactants compared to the maximum theoretical amount that you can get:

• The?actual yield?is the number of moles or mass of product obtained?experimentally
• The?theoretical?yield?is the number of moles or mass obtained by a reacting mass calculation

Answer:

Step 1:?The symbol equation is:

Zn (s)+CuSO₄ (aq)→ZnSO₄ (aq)+ Cu (s)

Step 2:?Calculate the amount of zinc reacted in moles

Step 3:?Calculate the maximum amount of copper that could be formed from the molar ratio:

Since the ratio of Zn(s) to Cu(s) is 1:1 a maximum of 0.10 moles can be produced

Step 4:?Calculate the maximum mass of copper that could be formed (theoretical yield)

mass=molxM=0.10molx63.55g mol^-1=6.4 g (2 sig figs)

Step 5:?Calculate the percentage yield of copper