ChemistryGCSE & IGCSEYield & Economy

Atom economy formula

The atom economy formula as it is used in GCSE Chemistry, taken from the GCSE Chemistry formula sheet.

The formula

\% \text{ atom economy} = \dfrac{M_r \text{ of desired product}}{M_r \text{ of all reactants}} \times 100

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Check every quantity is in consistent units before you substitute, then substitute in one step so the working stays easy to follow.
Show the rearrangement rather than jumping to the answer, and give the final value to the accuracy the question asks for.

\% \text{ yield} = \dfrac{\text{actual mass}}{\text{theoretical mass}} \times 100

\% \text{ mass} = \dfrac{\text{mass of element}}{M_r} \times 100

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