In a Mannich reaction, $0.25\text{mol}$ of formaldehyde, $0.30\text{mol}$ of piperidine, and $0.20\text{mol}$ of acetophenone are mixed under acidic conditions. After work‑up, $0.15\text{mol}$ of the Mannich product is isolated. Calculate the percentage yield based on the limiting reagent.

Step-by-step solution

1. Identify the stoichiometry: one mole of formaldehyde reacts with one mole of amine and one mole of ketone to give one mole of Mannich product.
2. Compare the moles available: Formaldehyde: 0.25 mol Piperidine: 0.30 mol Acetophenone: 0.20 mol
3. The reagent in smallest amount is acetophenone (0.20 mol); it is the limiting reagent.
4. Theoretical yield of Mannich product = 0.20 mol (one mole per mole of limiting reagent).
5. Actual yield = 0.15 mol
6. Percentage yield = $\frac{0.15}{0.20}\times 100=75.0$.

Concept tested: Percent yield in Mannich reaction

Published 16 October 2026 · How this solution was prepared and checked