Equivalent mass = molar mass ÷ n-factor
For acids: equivalent mass = molecular mass ÷ basicity
For bases: equivalent mass = molecular mass ÷ acidity
For salts: equivalent mass = molecular mass ÷ total positive or negative charge involved
For redox substances: equivalent mass = molecular mass ÷ number of electrons lost or gained per molecule
For elements: equivalent mass = atomic mass ÷ valency
Determine the n-factor first
Divide the molar mass by the n-factor
Use the reaction context to find the correct n-factor
Express the result in grams per equivalent