Chapter 4, Problem 130IAE

A fundamental principle green chemistry is atom economy (AE). AE is a measure of how many atoms from the starting materials are incorporated into the desired product. For example, if a reaction incorporates all the reactant atoms into the product of interest, the reaction has a percent AE of 100%. Toobtain percent AE for a reaction, we calculate the mass of the desired product that can be formed from a stoichiometric mixture of reactants, andcompare this mass with the total mass of that reaction mixture. (In a stoichiometricmixture of reactants, none of the reactants are present excess; the mole amounts are in the same ratio as the stoichiometriccoefficients).

$\text{\%AE=}\frac{\text{mass}\left({\text{m}}_{\text{p}}^{\text{l}}\right)\text{of the desired product P}}{\text{total mass of a stoichiometric micture of reactants}}\text{×100}$

The prime (') on the symbol for the mass of desired product serves to remind us that mass is calculated for a stoichiometric mixture of reactants. Use the definition above to calculate the percent AE for the following reactions, both of which can be used to make ${\text{C}}_{\text{5}}{\text{H}}_{\text{5}}{\text{NH}}_{\text{2}}$ the desired product.