Chemical equilibrium is the point in a chemical reaction where both reactants and products stabalise within the concentration.

We can model the position of a chemical equilibrium by considering the Gibbs free energy of reactants and products.

Gibbs free energy can be used to calculate the reversible potential of the thermodynamic reaction.

This is shown by a graph of Gibbs free energy reaching a minimum.

The variation in the amount of reactant or product, and it's effect on chemical equilibrium, can be demonstrated to students by:

  • Asking two students to hold opposite ends of a rope, one representing the reactants and the other the products
  • The lowest point on the rope is the position of equilibrium
  • Students can observe the movement of the lowest point as the two students move the rope up and down

Danny Clift, Head of Physics at St Angela's Ursuline School, was inspired to suggest these teaching ideas after hearing Dr Wuge Briscoe (University of Bristol) speak about Energy and the 2nd Law of Thermodynamics at a New Teacher Subject Day for Chemistry.

Schools Programme members and course attendees can download the resources from the event in the PTI Staffroom.

Want to discover more inspiring subject knowledge? See our upcoming courses and events for 2017, including our New Teacher Subject Days course for ChemistryBiology and Physics.

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