The mole, molar mass and concentration

Learning objectives

Define the mole in terms of the Avogadro constant 6.02 × 10²³ mol⁻¹, and convert between amount of substance, number of particles and mass using n = m/M

Calculate relative formula mass and molar mass from relative atomic masses, and use them to convert between mass and amount for elements, compounds and hydrated salts

Determine an empirical formula from percentage composition or from combustion data, and deduce the molecular formula when the relative molecular mass is known

Calculate concentration in mol dm⁻³ and in g dm⁻³, convert between the two, and calculate the concentration of a solution prepared by dilution using c₁V₁ = c₂V₂

Express the concentration of a very dilute solution in parts per million, and convert between ppm and mol dm⁻³ for an aqueous solution

Apply the mole concept to solids, solutions and gases in the same calculation, choosing the correct route from mass, volume or concentration to amount of substance