Audit apparent yield against independent product purity

Define the numerator before calculating yield

Theoretical yield is the maximum amount of the desired product implied by an independently established limiting-reactant account. Actual yield should refer to that same product, not every gram recovered from a vessel. Residual solvent, other products or contamination can make a gross mass larger than the desired-product amount .

Apply an independent mass-fraction result

For a stipulated10.0 g theoretical pure-product mass, recovering11.0 g at product mass fraction .80 gives 8.8 g actual product and 2.2 g nonproduct. Apparent gravimetric yield is 110%, but the purity-corrected yield is 88%. Neither division changes the physical sample; the difference is the meaning assigned to the measured numerator.

Do not hide an inconsistent result

If the same11.0 g is independently declared pure product, the corrected yield remains110%. That is inconsistent with the stipulated10.0 g upper bound under the stated assumptions. The workbench flags it rather than clipping the answer to 100%. Candidate explanations include an incorrect limiting inventory, wrong product formula, purity calibration error, weighing error or an incomplete reaction model.

Distinguish reaction and recovery

Even a valid corrected yield combines chemical formation and subsequent recovery. A low recovered amount does not by itself show that little product formed: some may remain dissolved or be lost during separation. Conversely, an apparently large recovered mass does not prove high conversion. Additional measurements are needed to separate conversion, selectivity, purity and recovery.

Transfer with a changed bound

A new virtual packet has theoretical pure mass 12.0 g, recovered gross mass 10.0 g and product fraction .90. Desired product is 9.0 g and corrected yield75%, while apparent yield is about 83.3%. Explain which quantity changed rather than treating the two percentages as competing arithmetic answers. The lesson supplies all values and requests no preparation, isolation or drying procedure.

Sources and evidence boundary

Conceptual sources checked 30 October 2026: Theoretical and actual yields. All prose, cases, code and diagrams are original. The supplied models are not measured structures, a performed laboratory investigation or certification of independent mastery. No chemical handling, heating, pressure vessel or cryogenic experiment is requested. Retain predictions, contrasting evidence and a changed-case explanation.