Unit 4: The Chemists tools


Students should..

  • - have an insight into the size of atomic systems.
  • - Understand the law of constant composition and how it relates to chemical formulae
  • - Understand the law of conservation of matter and how it relates to chemical equations
  • - understand the relationship between moles and mass
  • - be able to calculate reacting masses in equations by ratio and by the use of moles.
  • - be able to calculate the formula of a simple binary substance through experiment
  • - understand the experimental concepts of reliability, precision and accuracy


Pre-unit revision

  • Atoms and molecules revision to include relative molecular mass
  • Formulae and valency revision - the law of constant composition
  • Law of conservation of mass
  • Chemical equations.
  • Construction and balancing equations

The mole concept

Introduction to moles and reacting masses

Moles calculations

Cwk, Hwk calculations on moles, RMM, and reacting masses

Expt 1: Determining the formula of magnesium oxide

Expt 2: Determining the equation for the decomposition of magnesium carbonate

Expt 3: Reduction of copper(II) oxide

Planning: Determing the water of crystallisation in hydrated copper(II) sulphate

Virtual experiment: The reduction of metal oxides - data processing

Unit test: Formulae, equations, moles and mass


Formulation self-test

Formula recognition


Formulation 1

Formulation 2

Balancing equations 1

Valency table

IsisSoft 2014