THE CHEMICAL EQUATION AND STOICHIOMETRY

As you already know, the chemical equation provides a variety of qualitative and quantitative information essential for the calculation of the combining weights (mass) of materials involved in a chemical process. Take, for example, the ombust ion of heptane
Stoichiometry (stoi-ki-om-e-tri) ? deals with the combining weights of elements and compounds. The ratios obtained from the numerical coefficients in the chemical equation are the stoichiometric ratios that permit you to calculate the moles of one substance as related to the moles of another substance in the chemical equation. If the basis selected is to be mass (Ibm, kg) rather than moles, you should use the following method in solving problems involving the use of chemical equations: (I) Use the molecular weight to calculate the number of moles of the substance equivalent to the basis; (2) change this number of moles into the corresponding number of moles of the desired product or reactant by multiplying by the proper stoichiometric ratio, as determined by the chemical equation; and (3) then
change the moles of product or reactant to a mass.