Chemical Changes and Structure (N5)
The key areas covered in this Unit are:
rates of reaction — average rate of reaction calculated from graph to show change in rate as reaction progresses
Colourless orange or blue (Demo) - a demo version of the Briggs-rauscher reaction as used in the antioxidants workshop.
Cool experiment (Demo) - endothermic reaction between barium hydroxide and ammonium thiocyanate.
Light sticks (Demo) - Effect of temperature on luminosity of glow-sticks (this can also be done as a class experiment)
Rhubarb, Rhubarb, Rhubarb (Demo) - Using a stick of rhubarb to stir a beaker of dilute potassium manganate VII, the solution goes clear.
Antioxidants - This is a range of investigations based around the Briggs-Rauscher oscillating reaction to look at antioxidant levels in fruits and teas (though the method can be adapted for any source of antioxidants).
Bleaching Blue Food Dye - Reaction to determine rate constant and order of reaction from the bleaching of blue food colouring by domestic bleach. (Workshop is aimed at Advance Higher but without the mathematics it can easily be adapted to this level).
Rhubarb Rhubarb - Using rhubarb to decolourise permanganate in order to follow the rate of reaction, looking at concentration and surface area (and possibly temperature)
Thiosulphate acid reaction - microscale - A small scale version of the classic investigation into rates of reaction. Use of small scale and a neutralising bach reduces the production of toxic SO2
atomic structure and bonding related to properties of materials — nuclide notation; isotopes and relative atomic mass; ions and ionic bonding; covalent molecular; covalent network and ionic lattices; physical properties of chemicals explained through bonding; chemical and ionic formulae including group ions
formulae and reaction quantities — balanced equations; gram formula mass, the mole, calculations relating mass, volume of solutions, concentration and moles
Formula of magnesium oxide - microscale - a small scale version of this classic reaction to determine the formula of magnesium oxide.
Water in a hydrated salt - microscale - a small-scale experiment to determine the stoichiometric amount of water in some hydrated salts.
acids and bases — dissociation of water into hydrogen and hydroxide ions; pH is related to the concentration of hydrogen and hydroxide ions in pure water, acids and alkalis; neutralisation titration
Colourful flowers (Demo) - Make paper 'flowers' soaked in different buffer solutions. Then spray indicator on and you get different colour flowers.
Rainbow reaction (Demo) - Form a rainbow of colours to illustrate the pH scale with HCl and sodium carbonate along the length of a burette
Conductivity - Activity using a (home made) conductivity flask to follow neutralisation reactions.
Conductivity - microscale - a microscale investigation into the conductivity of solutions.
Indicators - microscale - A look at pH and indicators and how to make universal indicator
Titration - microscale - a microscale version of a titration that does not require burettes. This particular experiment is investigating the acidity of vinegars.
Vinegar Cheats - a larger scale investigation into the possible watering down of vinegar in the school canteen.