Identify the number of moles needed: (n)
Use (n = dfrac{m}{M}) when you know mass and molar mass
Use (n = dfrac{m}{M}) with units: (m) in g, (M) in g/mol, (n) in mol
Calculate molar mass: add atomic masses from the periodic table for each element and sum according to the formula
Use (n = C times V) when you know concentration and volume (solutions)
Use (n = dfrac{P V}{R T}) for gases when you know pressure, volume, and temperature
Use (R = 0.082057 text{L·atm·mol}^{-1}text{·K}^{-1}) with (P) in atm, (V) in L, (T) in K
Convert temperature to Kelvin: (T(text{K}) = T(^circtext{C}) + 273.15)
Convert volume to liters and mass to grams before substituting into formulas
Use stoichiometry from a balanced equation: convert given moles to moles of the target using coefficients
If given amount of substance in grams of a gas: find molar mass first, then use (n = dfrac{m}{M})
If given particles: use (n = dfrac{N}{N_A}) where (N_A = 6.022 times 10^{23} text{mol}^{-1})
If given percent composition: determine mass of each element, convert each to moles, then use the total or ratio as required