In a chemical reaction, the mass of the products a. is less than the mass of the reactants b. is greater than the mass of the reactants c. is equal to the mass of the reactants d. has no relationship to the mass of the reactants 12. the first step in most stoichiometry problems is to a. add the coefficients of the reagents c. convert given quantities to volumes b. convert given quantities to moles d. convert given quantities to masses