Atom Economy Calculator Formula

Understand the math behind the atom economy calculator. Each variable explained with a worked example.

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Formulas Used

Atom Economy

atom_economy = (mw_product / mw_all_products) * 100

Waste Fraction

waste_fraction = (1 - mw_product / mw_all_products) * 100

Variables

VariableDescriptionDefault
mw_productMolecular Weight of Desired Product(g/mol)180
mw_all_productsSum of MW of All Products(g/mol)220

How It Works

Atom Economy

Atom economy (atom efficiency) measures how much of the reactant atoms are incorporated into the desired product. It is a green chemistry metric independent of yield.

Formula

Atom Economy = (MW of desired product / sum of MW of all products) × 100%

Reactions with high atom economy produce less waste by design. Addition reactions (100% atom economy) are preferred over substitution or elimination reactions that generate byproducts.

Worked Example

A reaction produces a desired product (MW=180) and a byproduct (MW=40).

mw_product = 180mw_all_products = 220
  1. 01Atom economy = (180 / 220) × 100 = 81.82%
  2. 02Waste fraction = 100 - 81.82 = 18.18%

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