Stoichiometry Flashcards
Compound
a pure substance composed of two or more elements in a fixed proportion
Molecule
a combination of two or more atoms held together by covalent bonds and is the smallest unit of a compound that still displays the properties of that compound
Molecular weight
the sum of the atomic masses of the atoms in the molecule
Mole
the amount of a substance that contains the same number of particles found in a 12 g sample of carbon
mole = weight of sample (g) / molar weight (g/mol)
Gram-equivalent weight (GEW)
equivalents = weight of compound/gram equivalent weight
gram equivalent weight = molar mass/n
Law of constant composition
states that all samples of a given compound will contain the same elements in identical mass ratios
Empirical Formula
gives the simplest whole number ratio of the elements in a compound.
Molecular Formula
gives the exact number of each element in the compound and is a multiple of the empirical formula
Percent Composition
mass of x in formula / formula weight of compound x 100%
Law of Conversation of Mass
the mass of the reactants in a reaction must be equal to the mass of the products
Stoichiometric coefficients
used to indicate the number of moles of a given species involved in the reaction
Theoretical Yield
the amount of product that can be predicted from a balanced equation, assuming tha tall of the limiting reagent has been used, no competing side reactions have occurred, and all of the product has been collected.
Actual Yield
the amount of product isolated from the reaction experimentally
Percent Yield
used to express the relationship between the actual yield and the theoretical yield and is given by the following equation:
% yield = actual yield/theoretical yield x 100%
