Reversible reactions

The experiments in this section can be used to demonstrate reversible reactions and reactions involving dynamic equilibria.

While we are still at an early stage with this website it's probably more useful to look at the page with our complete list of experiments in alphabetical order. See the list on About this website.

We are starting with GCSE-level experiments.

Experiments

• The reaction between carbon dioxide and water

  The acidic nature of carbon dioxide in solution in water is explored using exhaled air as the source of the gas, leading to an explanation of the reaction involved.

• A reversible reaction involving hydrated copper(II) sulfate and its anhydrous form

  The thermal decomposition of hydrated copper(II) sulfate and its regeneration by reacting the anhydrous copper(II) sulfate product with water.

• An equilibrium involving chromate(VI) and dichromate(VI) ions

  The conversion of chromate(VI) to dichromate(VI) using acid and its reconversion using alkali is followed by colour changes.

• An equilibrium involving copper(II) ions

  The conversion of hexaaquacopper(II) ions, [Cu(H~2~O)~6~]^2+^, to tetraamminediaquacopper(II) ions, [Cu(NH~3~)~4~(H~2~O)~2~]^2+^, and their reconversion.

• Le Chatelier’s Principle: the effect of concentration and temperature on an equilibrium.

  The effect of changing the concentration of chlorine, and the temperature, on the equilibrium ICl(l) + Cl~2~(g) ↔ ICl~3~(s) is shown by means of colour and phase changes.

• Equilibria involving carbon dioxide in aqueous solution

  The effect of pressure on the solubility of carbon dioxide in water, and hence on the equilibria in solution, illustrates Le Chatelier’s principle and Henry’s law of gas solubility.

• Rechargeable commercial cells: the lead-acid accumulator

  A simple cell lead-acid cell is constructed and charged and discharged for varying lengths of time.

• Le Chatelier’s principle: the equilibrium between nitrogen dioxide and dinitrogen tetroxide

  The effect of pressure and temperature on an equilibrium mixture of nitrogen dioxide and dinitrogen tetroxide is followed by observing the changes in the colour of the mixture and its volume.

• Le Chatelier’s Principle: the effect of concentration on equilibrium

  Le Chatelier’s principle is illustrated by the effect of chloride ion concentration on the equilibrium between bismuth oxide chloride and bismuth trichloride in solution.

• Reaction of zinc with iodine

  In this experiment students note the differences between a metal and a non-metal, and their reaction to form a metal salt.

• Ammonia fountain

  This spectacular demonstration highlights the high solubility of ammonia in water. The ammonia is shown to form an alkaline solution.