24 Molar Concept, Molar Mass, Percent Composition, and Chemical Formulas Flashcards
“stoichieon”
element
“metron”
measure
quantitative study of products and reactants in chemical reactions
stoichiometry
branch of chemistry
stoichiometry
application of Laws of Definite and Multiple Proportions and Conservations of Mass and Energy
stoichiometry
sum of number of neutrons and protons in atomic nucleus
mass number
mass of atom of chemical element in atomic mass units (amu)
atomic mass
atoms of same element which have diff mass number
isotopes
“relative atomic mass”
avg atomic mass
formula for avg atomic mass
[(% x amu) + (% x amu)]/100
amount of substance
mole (mol)
contains as many elementary entities as there are atoms in exactly 12g of C12
mole (mol)
Avogadro’s number
N(A)
mass of 1 mole of atoms in grams
molar mass
mol mass in amu = mol mass in g
yes
sum of atomic masses in molecule
molecular mass (molecular weight)
sum of atomic mass in formula unit of an ionic compound
formula mass
percent by mass of each element in a compound
percent composition
obtained by dividing mass of each element by molar mass of compound and multiplying by 100
percent composition
formula for percent composition
[(n x molar mass of element)/molar mass of compound] x 100%
n - num of moles
formula for formula mass
n x atomic mass + n x atomic mass
composition of mols and ionic compounds
chemical formula
elements present, simplest whole number ratio of their atoms, not necessarily actual num of atoms
empirical formula
exact no of atoms of each element; true formulas
molecular formula
formula for empirical formula
(compound’s molar mass x elements % composition in decimals)/element’s atomic mass
