Reacting 1.274 g of CuSO4 with excess zinc gives 0.392 g of copper, against a theoretical 0.5072 g. What is the percent yield?

1. Zinc is in excess, so copper sulfate is the limiting reactant and fixes the theoretical yield. 2. Converting 1.274 g of CuSO4 through 159.62 g/mol and then 63.55 g/mol gives 0.5072 g of copper. 3. The actual yield collected was 0.392 g of copper. 4. Percent yield is 0.392 divided by 0.5072, then multiplied by 100. 5. That division gives 0.7729, so the percent yield is 77.3%. 6. Dividing the other way round gives 129%, which is impossible and flags the reversed formula. 7. Rounding only at the end keeps the third significant figure trustworthy. _Source: OpenStax Chemistry (CC BY 4.0), Ch 4 "Stoichiometry of Chemical Reactions", section 4.4 Reaction Yields_