Stoichiometry Flashcards
Compound
A pure substance composed of 2 or more elements in a fixed proportion
Molecule
A combination of 2 or more atoms held together by covalent bonds
Formula mass
The sum of the atomic masses of each constituent atom according to the empirical formula
Molecular weight
The sum of the atomic masses of the atoms in the molecule
Molar mass
The mass of one mole of a compound
n = m/MW
Mole
The amount of a substance that contains the same number of particles found in a 12 g sample of carbon-12
Gram-equivalent weight
Determine the number of equivalents a compound contains; define a measure of reactive capacity
GEW = molar mass/n
Law of constant composition
All samples of a given compound will contain the same elements in identical mass ratios
Empirical formula
The simplest whole number ratio of the elements in a compound
Molecular formula
The exact number of atoms of each element in a compound
Percent composition
The mass percent of the element in a specific compound
% composition = (mass of X in formula/formula weight of compound) X 100%
Law of conservation of mass
The mass of the reactants in a reaction must be equal to the mass of the products
Stoichiometric coefficients
Indicate the number of moles of a given species involved in the reaction
Limiting reagent
The reactant consumed first in a reaction. Limits the amount of product that can be formed
Excess reagent
The reactant that remains after all the limiting reactant is consumed
