What is the Yield? What is it Dependent on? | -This is the Amount of Products you get from a Reaction.
-This is simply down to how many Reactants you start with |
What is the Percentage Yield? What is the Formula for it? | Percentage Yield = [Actual Yield / Theoretical Yield] x 100
-This is simply a Percentage, on how much you Really Get from the Reaction [100% = All the Reactants have been Converted to Products] |
What is the Theoretical Yield of a Reaction? | -This is simply the Mathematical side of things
-Its just the Mass of Product you would make if All the Reactants was Converted to Products
-This can be Calculated from the Balanced Reaction Equation |
In a Industrial Reaction, Iron Oxide reacts with Carbon to make Iron:₃
2Fe₂O₃ + 3C --> 4Fe + 3CO₂
What is the Percentage Yield if you had 50kg of Iron Oxide, and made then 18.9 kg of Iron | -First, find the Relative Formula Mass of Iron Oxide, and Iron
[2x55.8 + 3x16 = 159.6] [Fe = 55.8]
-Second, find out how many moles of the Reactant [Iron Oxide]
[Moles = Mass / Mr --> Moles = 50000g / 159.6 = 313 Moles
-Third, use the Ratio in the Balanced Equation to find Moles of Iron
[If 2 Moles of Iron Oxide = 4 Moles of Iron -->313:626]
-Fourth, find out the Theoretical Yield by Converting the Number of Moles into Mass--> [Mass = M x Ar --> Mass =626x55.8=34.9kg]
-Fifth, Substitute back into the Yield Formula
[PY = 18.9/34.9 x 100 = 54% |
Why is it Important to keep Yield as High as Possible? | -If it has a Low Yield, then that means a Lot of the Reactants will be Wasted, so Reactions that give out the Highest Yield is Valued
-However, Cost is another Factor to think about |