Use the formula: moles = mass ÷ molar mass
Measure the mass of the substance in grams
Find the molar mass of the substance in g/mol
Divide the mass by the molar mass
Use the formula: moles = number of particles ÷ Avogadro’s number
Count the number of atoms, molecules, or ions
Divide by 6.022 × 10^23
Use the formula: moles = volume ÷ molar volume for gases
Measure the gas volume in liters
Divide by 22.4 L/mol at STP
Use the formula: moles = concentration × volume for solutions
Measure the concentration in mol/L
Measure the volume in liters
Multiply concentration by volume