Reaction Yield

What is this formula?

Reaction yield measures the efficiency of a chemical reaction by comparing the amount of product actually obtained with the maximum amount predicted by stoichiometry.

When to use it

Use this formula after completing a reaction to evaluate process performance, compare reaction conditions, and identify losses due to side reactions, incomplete conversion, purification, or handling.

Example

Given:

Actual product obtained = 0.82 mol

Theoretical product = 1.00 mol

Formula:

Y = (nactual / nth) × 100

Substitution:

Y = (0.82 / 1.00) × 100

Result:

Y = 82%

The reaction produced 82% of the theoretical product.

Applications

Organic synthesis

Medicinal chemistry

Process development

Industrial chemistry

Reaction optimization

Note

Reaction yield is often reported using mass, moles, or isolated product quantity. The calculation remains the same as long as the actual and theoretical quantities are expressed in the same units. Yields greater than 100% usually indicate impurities, solvent retention, measurement errors, or incomplete drying of the product.