Formulae, equations and relative masses

Learning objectives

State the formulae of the elements and compounds met in the course, define molecular formula, and deduce the formula of a simple compound from the relative numbers of atoms in a model or diagram

Deduce the formula of an ionic compound from the charges on its ions or from a model or diagram of its lattice (Extended)

Construct word equations and balanced symbol equations, including the state symbols (s), (l), (g) and (aq), to show how reactants form products

Construct balanced symbol equations, including ionic equations for reactions such as precipitation and neutralisation, from information given (Extended)

Define relative atomic mass, Ar, as the average mass of the isotopes of an element compared to 1/12 of the mass of a ¹²C atom, define relative molecular (or formula) mass, Mr, as the sum of the relative atomic masses, and calculate Mr from Ar values on the Periodic Table

Calculate reacting masses in simple proportion from given masses, without using the mole, and state that the concentration of a solution can be measured in g/dm³ or in mol/dm³