Equilibrium

The activities in this category include experiments relating to equilibria in solution, gaseous equilibria, acid-base equilibria and redox 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.
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Experiments

• 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.

• Distribution of iodine between two immiscible solvents

  A qualitative investigation into the way a solute, iodine, can distribute itself between two immiscible solvents, aqueous potassium iodide and cyclohexane.

• 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.

• 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.

• Indicators and dry ice: demonstration

  A colourful and spectacular demonstration in which solid carbon dioxide (dry ice) is used to cause a colour change in one or more indicators.

• Ammonia fountain

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