Percentage Yield
Chemistry: Edexcel IGCSE, topic 5.1.19
Percentage Yield
The percentage yield for any reaction is always less than 100%. The following 4 factors make sure the percentage yield of reactions stays below 100%:
Incomplete reactions
- An incomplete reaction can happen because:
- The reaction is very slow and hasn't been given enough time to happen.
- The reaction is reversible and some of the products have been converted back into reactants.
Waste
- Some of the chemicals will remain stuck to the apparatus and will be wasted.
Extraction
- It might be difficult to fully separate the product from the reaction mixture.
Side reactions
- Unexpected reactions (side reactions) can happen. This may mean that the intended product is not created.
Test yourself on Percentage Yield
To understand percentage yield, it can be useful to imagine you are baking a cake...
4 factors that reduce percentage yield
Why do side reactions lower the percentage yield of a reaction?
What must be true of a reaction for it to reach a percentage yield of 100%?
What features of a reaction make it more likely to be incomplete?