Percentage Yield
Chemistry: AQA GCSE Higher, topic 3.1.16
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
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?
Why does waste of chemicals lower the percentage yield of a reaction?