Percentage Yield

The amount of product you get is known as the yield
The more reactants you start with, the higher the actual yield will be
- But the percentage yield doesn’t depend on the amount of reactants you started with, it’s a percentage
- Percentage yield = mass of product actually made(g) / maximum theoretical mass of product x 100
- Maximum theoretical mass can be calculated using balanced reaction equation
Percentage yield is always somewhere between 0 and 100%
100% yield means that you get all the product you expected to get
0% yield means that no reactants were converted into products
Industrial processes should have as high a percentage yield as possible to reduce waste and reduce costs

In real life, you never get a 100% yield
Some products or reactant always gets lost along the way, and that goes fr big industrial process as well as school lab experiments
Depends on what sort of reaction it is and what apparatus is being used

In reversible reactions the products can turn back into reactant so the yield will never be 100%
- For example, in the Haber process at the same time as the reaction N2 + 3H2 - 2NH3 is taking place, the reverse reaction is also happening
- This means it never goes to completion