Atom Economy (Triple Only)

• Percentage Atom Economy: A measure of the proportion of atoms in the reactants that are converted into the desired product(s).

• Importance:

  • Used to assess the efficiency and sustainability of a chemical process.

  • Higher atom economy = less waste, more sustainable and cost-effective.

• Atom economy is based purely on the balanced chemical equation (not on experimental yield).

• It does not depend on reaction conditions or experimental success.

• It focuses on how many of the atoms in the reactants end up in the desired product.

Explanations

Why Atom Economy Matters

• Economic: Less waste means lower disposal costs and higher profits.

• Environmental: Less pollution and waste production.

• Ethical: Green chemistry principles promote sustainability and minimal resource use.

Choosing Reactions

• Reactions with fewer by-products and only one main product tend to have higher atom economy.

• Addition reactions generally have 100% atom economy, since all atoms become part of the product.

• Substitution and elimination reactions usually have lower atom economies due to by-products.

Example 1 – High Atom Economy Reaction

Reaction:

Mr Values:

Addition reaction No waste, high efficiency.

Example 2 – Lower Atom Economy Reaction

Reaction:

Desired product:

• Total of reactants = 106 + 2(36.5) = 179.0

Less efficient due to waste products