Atom Economy Calculator

What is Atom Economy?

Atom economy is a measure of the efficiency of a chemical reaction in terms of the utilization of reactant atoms in the desired product. It is defined as:

Atom Economy = (Molecular Weight of Desired Product / Sum of Molecular Weights of All Products) × 100%

A higher atom economy indicates a more efficient reaction with less waste. An ideal reaction would have an atom economy of 100%, meaning all reactant atoms end up in the desired product.

How to Use This Calculator

1. Enter the Molecular Weight of your Desired Product: This is the main product you want to form in the reaction, measured in grams per mole (g/mol).
2. Enter the Molecular Weights of Other Products: List the molecular weights of all other products formed in the reaction, separated by commas. For example, if your reaction produces CO₂ and H₂O, you would enter 44.01, 18.02.
3. Click "Calculate": The calculator will compute the total molecular weight of all products and then calculate the atom economy percentage.
4. Interpret the Results: The calculator displays the total molecular weight of all products and the atom economy percentage. Compare this value to reactions involving the same reactants to assess efficiency.

Example Calculation

Consider the reaction:

CH₃COOH (Acetic Acid) + C₄H₁₀ (Butane) → CH₃COOC₄H₉ (Butyl Acetate) + H₂O (Water)

The molecular weights are:

• CH₃COOH: 60.05 g/mol
• C₄H₁₀: 58.12 g/mol
• CH₃COOC₄H₉: 116.16 g/mol
• H₂O: 18.02 g/mol

Using the calculator:

1. Desired Product MW: 116.16
2. Other Products MW: 60.05, 58.12, 18.02
3. Total Products MW: 116.16 + 60.05 + 58.12 + 18.02 = 252.35
4. Atom Economy: (116.16 / 252.35) × 100% ≈ 46.0%

This means approximately 46.0% of the reactant atoms are incorporated into the desired product (butyl acetate).

Applications

Atom economy is particularly useful in green chemistry for evaluating and improving synthetic pathways. It helps identify reactions that minimize waste and reduce environmental impact.