Safety boundary
Use paper-token models, supplied calculations, and simulations only. No unsupervised chemical reactions are required.
Explicit chemistry instruction
Actual yield is the measured amount of product recovered. Percent yield = actual/theoretical ×100%.
A yield below 100% can reflect incomplete reaction, side reactions, transfer loss, purification loss, or measurement uncertainty.
A value above 100% usually signals wet/impure product, measurement error, or a problem with the theoretical model—not 'extra chemistry success.'
Vocabulary: actual yield; percent yield; recovery; purity; uncertainty.
Worked example
Theoretical yield is 10.0 g and actual yield is 8.50 g, so percent yield=85.0%.
Guided question
Actual yield is 12.4 g and theoretical yield is 15.5 g. Calculate percent yield.
Independent work
- Calculate percent yield for four datasets.
- Diagnose one plausible cause for low yield.
- Explain one reason a measured yield might exceed 100%.
Misconception check
Percent yield above 100% is not physically interpreted as producing more pure product than stoichiometry allows.
Formative check
What denominator is used in percent-yield calculation?
Reveal response
Theoretical yield.
Mentor evidence conference
Ask Archaemenes to audit the limiting-reactant logic, conversion chain, and evidence interpretation.
Teacher guidance
Foundation: Use a percent-yield organizer.
Core: Calculate and interpret yield.
Extended: Evaluate competing explanations for anomalous yield.