Chapter 3 Memory Bank

m

mass, normally in grams

n

amount in moles

MM

molar mass, in g/mol

N

number of particles

N_A

Avogadro's number = 6.022 x 10^23 particles/mol

coefficient

number before a formula; changes the number of whole particles or moles

subscript

number inside a formula; changes the identity and atom count of a compound

actual yield

product actually obtained

theoretical yield

maximum product predicted by stoichiometry

moles from mass formula

n = m / MM

mass from moles formula

m = n x MM

particles from moles formula

N = n x N_A

moles from particles formula

n = N / N_A

grams -> moles

divide by molar mass

moles -> particles

multiply by 6.022 x 10^23

particles -> moles

divide by 6.022 x 10^23

moles -> grams

multiply by molar mass

universal conversion map

grams -> moles -> particles; particles -> moles -> grams

stoichiometry map

grams A -> moles A -> moles B -> grams B

moles A -> moles B conversion factor

the balanced-equation coefficients

important stoichiometry rule

never directly compare grams