Atoms, molecules and stoichiometry

Learning objectives

Define relative atomic, isotopic, molecular and formula mass against one-twelfth of the mass of a carbon-12 atom, and use the Avogadro constant (6.02 × 10²³ mol⁻¹) to convert between amount in moles and number of particles

Write formulae of ionic compounds from ion charges and Roman-numeral oxidation states, and construct balanced full and ionic equations with state symbols, leaving out spectator ions

Calculate empirical and molecular formulae from percentage composition or combustion data, and find the water of crystallisation in a hydrated salt such as MgSO₄·xH₂O

Calculate reacting masses, percentage yield and the limiting or excess reagent using n = m/M and the mole ratio from a balanced equation

Calculate gas volumes with 24.0 dm³ mol⁻¹ at room conditions and amounts in solution with n = cV, including titration results, and deduce the stoichiometry of a reaction from experimental quantities