Videos

Welcome! We actually have a YouTube channel that features our experiments and demonstrations – but hey, if you’re too lazy to head over we understand, you can find the videos and explanations right here:

      1. Heat-Catalysed Nitration of Cellulose
      2. Dissolving Polystyrene Cups in Acetone
      3. Glycerol Oxidation with Potassium Permanganate
      4. Thunderstorm in a Test Tube

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Heat-Catalysed Nitration of Cellulose

Replacing -OR groups on chain-linked cellulose with -ONO2 nitro functional groups using concentrated nitric acid. Since the reaction is kinda slow to get started we use heat from a bunsen burner as a catalyst. Remember that nitric acid is a strong oxidiser and shouldn’t be mixed with organic compounds. Really, do not try this at home. We mean it.


Dissolving Polystyrene Cups in Acetone

In chemistry, we are often taught that ‘like dissolves like’. However in this case we see polystyrene (a non-polar hydrocarbon) dissolving in acetone (a somewhat polar solvent). You wouldn’t expect to see acetone’s dipole-dipole interactions (from its C=O bond) make way to accommodate polystyrene as bond-wise as the (enthalpic) energy of the solution would be higher. This is where entropic factors come into play. Upon dissolution of polystyrene, the ions in solution have more ‘ways’ to be arranged compared to the solid. This higher entropy is what drives the reaction. This is also true for many salts, where breaking ion-ion bonds and forming ion-dipole (ion-solvent) bonds is not necessarily enthalpically favorable!


Glycerol Oxidation with Potassium Permanganate

Glycerol added to potassium permanganate produces such a neat flame, doncha think? The Mn(VII) is reduced while glycerol is oxidixed to mainly carbon dioxide and steam. Spontaneous and exothermic!


Thunderstorm in a Test Tube

Potassium permanganate (KMnO4) crystals dropped into a test tube containing an ethanol layer on top of sulfuric acid. The KMnO4 sinks to the bottom and is converted to Mn2O7 (potassium heptoxide – a contact explosive!) This then oxidizes the ethanol layer to acetic acid, while Mn2O7 is reduced, producing oxygen, which combined with the heat and ethanol, produces loud visible ‘pops’!


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