Unit 6: Stoichiometry

stoichiometry

way of converting between moles of materials in a chemical reaction; the calculation of the amount of substances in a chemical reaction from the balanced equation

mole ratio

uses the coefficients in the balanced equation

limiting reactant/reagent

is the reactant that determines the amount of product that can be formed in a chemical reaction

actual yield

describes the amount you actually make in the lab

Theoretical yield

how much you should be able to make based on the amounts given in the problem

percent yield

Way to describe how close your experimental yield was to the amount predicted. Percent yield can be less than or greater than 100. Percent yield = A/T x 100

true or false: the unknown quantity in a stoichiometry problem is ALWAYS a product

false, the given and the unknown may both be reactants, both be products, or one may be a reactant and the other is a product

excess reactant

is the reactant that is intially present in a greater amount that will eventually be reacted, some of this reactant is left over after the reaction is complete

stoichiometric mixture

all reactants are consumer and no excess reactant exists

a high percent yield is desirable in chemistry, is it possible to get more than 100% yield?

percent yields greater than 100% are possible if the measure product of the reaction contains impurities that cause its mass to be greater than it actually would be if the product was pure