Chapter 4: Compounds & Stoichiometry Flashcards
molecule
2 or more atoms held together by covalent bonds
atomic weight
the weighted average of the masses of the naturally occurring isotopes of an element (not their weight)
molecular weight
the sum of the atomic weights of all the atoms in a molecule
molar mass
the mass of one mole of a compound
g/mol
how to determine moles in a given sample substance
moles = mass of sample (g) / molar mass (g/mol)
empirical formula
gives the simplest whole-number ratio of the elements in the compound
molecular formula
gives the exact number of atoms of each element in the compound
percent composition
definition
the percent of a specific compound that is made up of a given element
ex. percent of carbon in glucose molecule
percent composition
definition
the percent of a specific compound that is made up of a given element
percent composition (by mass)
equation
percent composition = [ (mass of element in formula) / (molar mass) ] x 100%
combination (synthesis) reactions
two or more reactants combine to form one product
decomposition reactions
a single reactant is chemically broken down into two or more products
how to determine moles in a given sample substance
moles = mass of sample (g) / molar mass (g/mol)
combination (synthesis) reactions
two or more reactants combine to form one product
decomposition reactions
a single reactant is chemically broken down into two or more products
combustion reactions
a fuel (usually a hydrocarbon) and an oxidant (typically oxygen) react, forming the 2 products H2O and CO2
displacement reactions
atoms or ions of one compound are replaced with atoms or ions of another compound
single-displacement reactions
an atom or ion of one compound is replaced by an atom or ion of another element