What is the equation for calculating atom economy?

The correct formula for calculating atom economy is based on the relationship between the relative formula mass of the desired products and the total relative formula mass of all reactants involved in a chemical reaction. This measure indicates how efficiently a reaction utilizes its reactants to produce useful products.

In this context, atom economy is significant because it reflects the proportion of starting materials that end up as desired products rather than by-products. A higher atom economy is generally desirable as it means that the process wastes less material and can be more sustainable.

Using this formula, you take the relative formula mass of the desired products—which is the component of the products that fulfills the purpose of the reaction—and divide it by the total relative formula mass of all reactants used, then multiply by 100 to express it as a percentage. This calculation allows chemists to evaluate and optimize chemical processes for efficiency and environmental sustainability.