Representing Chemical Change

Balanced chemical equations

• Write and balance chemical equations.
• Interpret balanced reaction equations in terms of:
  
  • Conservation of atoms
  • Conservation of mass (use relative atomic masses)

Quantitative Aspects of Chemical Change

Molar volume of gases

• 1 mole of any gas occupies 22,4dm³:
  at 0°C (273K) and 1 atmosphere (101,3 kPa).

Volume relationships in gaseous reactions

• Interpret balanced equations in terms of volume relationships for gases, i.e. under the same conditions of temperature and pressure, equal number of moles of all gases occupy the same volume.

Concentration of solutions

• Calculate the molar concentration of a solution.

More complex stoichiometric calculations

• Determine the empirical formula and molecular formula of compounds.
• Determine the percentage yield of a chemical reaction.
• Determine percentage purity or percentage composition, e.g. the percentage CaCO₃ in an impure sample of seashells.
• Perform stoichiometric calculations based on balanced equations.
• Perform stoichiometric calculations based on balanced equations that may include limiting reagents.