chem mole n stoichiometry

molar mass (g/mol)

mass (g) divided by mol

no. of particles

mol x 6.02×10²³

concentration (mol/dm³)

mol divided by volume (dm³)

concentration (g/dm³)

mass (g) divided by volume (dm³

empirical formula

the simplest ratio of elements in a compound

what are the headers of the table for finding empirical formula

• mass or percentage

• Ar

• mole ratio

• simplest mol ratio

ALL WORKING IN 4S.F

limiting reagent

the reagent that is completely used up in a chemical reaction

limiting reagent

1. find mol of each reagent

2. 
   

formula for percentage yield

actual (mass/volume/amount)/theoretical (mass/volume/amount) x100%

percentage abundance of isotopes

Percentage of Isotope 1 = (|Average Mass - Mass of Isotope 2| / |Mass of Isotope 1 - Mass of Isotope 2|) x 100

formula for percentage purity

mass of pure/mass of impure x 100%

molecular formula

actual number of atoms in a compound

how to find molecular formula

1. “let molecular formula be (empirical formula)_n”

2. n = molecular formula/Mr

……...=ROUND TO NEAREST INTEGER

3. statement : “molecular formula of … is ….”